United States v. Singleton ( 2010 )


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  •         IN THE UNITED STATES COURT OF APPEALS
    FOR THE FIFTH CIRCUIT United States Court of Appeals
    Fifth Circuit
    FILED
    March 10, 2010
    No. 08-20546               Charles R. Fulbruge III
    Clerk
    UNITED STATES OF AMERICA
    Plaintiff - Appellee
    v.
    MICHELLE M VALENCIA
    Defendant - Appellant
    --------consolidated with 08-20573--------
    UNITED STATES OF AMERICA
    Plaintiff - Appellee
    v.
    GREG SINGLETON
    Defendant - Appellant
    Appeal from the United States District Court
    for the Southern District of Texas
    USDC Nos. 4:04-CR-514; 4:06-CR-80
    Before JOLLY, DeMOSS, and PRADO, Circuit Judges.
    Per Curiam:
    Michelle Valencia and Greg Singleton appeal wire fraud convictions
    arising from alleged efforts to manipulate natural gas markets. Each defendant
    No. 08-20546; 08-20573
    raises myriad issues on appeal, which we have considered carefully, along with
    an exhaustive review of the trial court’s record. Confident that each defendant
    received a fair trial and that the convictions rest on solid evidence, we affirm.
    I.
    We start with a factual overview of this case before delving into the
    particulars of the issues on appeal. We first describe the nature of defendants’
    job duties and give a sketch of the industry’s relevant practices. We then
    describe the course of proceedings brought against the defendants and the
    salient details of their four-week trial, which took place in July and August of
    2006. After documenting the facts and procedure, we consider the issues raised
    on appeal.
    A.
    The acts relevant to this appeal occurred in 2000 and 2001. During that
    time, Valencia was employed by Dynegy Marketing and Trade (“Dynegy”) in
    Houston, Texas, as a natural gas trader on Dynegy’s “West Desk.” Singleton was
    employed by El Paso Corporation (“El Paso”) as a natural gas trader for El Paso’s
    Merchant Energy segment in Houston. Natural gas is transported to consumers
    throughout North America via a network of pipelines. Natural gas produced in
    one region is interchangeable with gas produced elsewhere; the significant
    difference among regions is the cost of transport. Contracts for future delivery
    are traded on the New York Mercantile Exchange, or NYMEX. The most basic
    type of natural gas trade is a “physical” trade. A physical trade calls for
    delivery of a set volume of gas to the buyer at a particular delivery location. A
    “baseload” trade is a kind of physical trade. It calls for delivery of natural gas
    each day for an entire month. Most baseload trades are negotiated during a
    period at the end of the preceding month called “bidweek.” The most common
    unit of volume is one million British thermal units (“MMBtu”). Traders often
    buy or sell tens of thousands of MMBtu in a given transaction.
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    No. 08-20546; 08-20573
    The price of a trade can be set if traders agree upon a dollar amount at the
    time of trade; this is called a “fixed” price. However, traders can also opt to use
    prices which will be set in the future, called “index prices.” Commonly, traders
    use a price published either daily or monthly in a privately owned newsletter.
    These index prices also affect other natural gas transactions, such as swaps,
    where two traders agree to buy the same volume of gas from each other at the
    same time, but at different prices. In essence, swaps are financial transactions
    in which traders bet on, or hedge against, changes to an index price. Index
    prices also affect long-term supply contracts tied to index prices, options
    contracts, royalty payments, “tariffs” charged by pipelines, and futures contracts.
    The index prices published in two newsletters are relevant to this case:
    Inside FERC Gas Market Report (“Inside FERC”) and Natural Gas Intelligence
    (“NGI”). Each publication is privately owned and is not affiliated with any state
    or federal governmental entity. Inside FERC and NGI independently determine
    and publish index prices at the beginning of the month for natural gas delivered
    at dozens of different “hubs” across the country.       The publications gather
    monthly price data through surveys of natural gas traders. Inside FERC
    provides a Microsoft-Excel form for making reports, and instructs traders: “Only
    report FIXED-PRICE, BASELOAD DEALS negotiated during bidweek.”
    Traders must indicate the delivery points, prices, volumes, and dates of each
    trade. At the time of the acts alleged in this case, the publications requested,
    but did not require, identification of the other contracting party, or
    “counterparty.” After receiving bidweek trades from market participants, each
    publication publishes indices which purport to represent the price of natural gas
    at delivery points across the country. It was the policy of both Dynegy and El
    Paso to require its natural gas traders to submit such information each month.
    Both Valencia and Singleton bought and sold natural gas in order to fulfill
    long-term contracts, to utilize capacity, and ultimately, to bring profits to his
    3
    No. 08-20546; 08-20573
    respective employer. Each defendant was authorized to execute trades for
    physical delivery of gas throughout much of the western United States, as well
    as financially oriented trades based upon the same trading nodes. In addition
    to trading, Valencia and Singleton (along with other natural gas traders at their
    respective companies) were required to gather and submit bidweek trade
    information to Inside FERC and NGI. The government alleged that defendants
    submitted, or caused to be submitted, reports with false information to the
    publications in a scheme to manipulate the price of natural gas. Each defendant
    allegedly sought to raise the index price if the trader or his company had a net
    long position, i.e., had excess gas to sell, or lower the index price if he had a net
    short position, i.e., needed to purchase additional gas to meet contractual
    obligations. Valencia’s and Singleton’s alleged misrepresentations included
    reporting trades which never occurred, misstating the price or volume of real
    trades, and omitting real trades. By swaying gas indices one way or another at
    certain locations, Valencia and Singleton could allegedly boost their monthly
    performance and increase profits for their respective companies.              Better
    performance would redound to the benefit of the trader in the form of promotions
    or higher year-end bonuses.
    B.
    Michelle Valencia was indicted on January 22, 2003. She was initially
    charged with three counts of false reporting under the Commodities Exchange
    Act (“CEA”), in violation of 7 U.S.C. § 13(a)(2), and four counts of wire fraud, in
    violation of 18 U.S.C. §§ 2 and 1343. Upon Valencia’s pre-trial motion, the
    district court dismissed certain portions of the indictment charging Valencia
    with delivering or causing to be delivered false or misleading reports under the
    CEA. See United States v. Valencia, 
    2003 WL 23174749
    , at *19-21 (S.D. Tex.
    Aug. 25, 2003), vacated and modified upon reconsideration, 
    2003 WL 23675402
    ,
    at *4-5 (S.D. Tex. Nov. 13, 2003). The court ultimately reasoned that the false
    4
    No. 08-20546; 08-20573
    reporting provision of the CEA was unconstitutionally overbroad because it did
    not contain a sufficient mens rea requirement. See 
    2003 WL 23675402
    , at *4-5.
    In an interlocutory appeal, a panel of this Court held that the statute could be
    construed so as to avoid constitutional infirmity, and reversed. United States v.
    Valencia, 
    394 F.3d 352
    , 355 (5th Cir. 2004).       The Supreme Court denied
    Valencia’s petition for writ of certiorari. Valencia v. United States, 
    544 U.S. 1034
    (2005).
    A second superseding indictment was filed as to Valencia on March 8,
    2006. It alleged that she conspired with Singleton from July to September of the
    year 2000 to violate the CEA. Valencia was also alleged to have emailed over
    twenty reports to Inside FERC and NGI between December 30, 1999, and
    January 31, 2002, and also caused other employees to email such reports. The
    reports “affected and tended to affect index prices, and thereby, the price of
    natural gas.”    False information in the reports would affect the indices,
    increasing the profitability of Valencia’s trades. Valencia was charged with one
    count of conspiracy to violate the false reporting provision of the CEA, thirteen
    counts of false reporting under the CEA, and nine counts of wire fraud.
    Singleton was indicted on November 17, 2004. Like Valencia, Singleton
    was accused of having sent reports with false information to Inside FERC and
    NGI about trade volumes and prices between July and September of 2000. In
    a superseding indictment filed March 8, 2006, Singleton was charged with one
    count of conspiracy to violate the false reporting provision of the CEA, five
    counts of false reporting under the CEA, three counts of wire fraud, and one
    count of obstruction of justice for impeding an investigation concerning the false
    trades. In light of the nexus of common acts alleged, the defendants and
    government agreed to a joint trial. After numerous continuances, trial was set
    for July 2006.
    5
    No. 08-20546; 08-20573
    Pretrial discovery involved production and analysis of vast amounts of
    data. Thousands of hours of telephone calls and other voice recordings, emails
    from scores of individuals, reams of paper records, and multiple electronic
    databases comprised the universe of potentially relevant material obtained from
    Dynegy, El Paso, the corporate parents of Inside FERC and NGI, governmental
    agencies, and other players or stakeholders in the natural gas markets. Before
    trial commenced, and during the trial itself, the parties often disagreed as to
    whether the government had turned over all relevant and discoverable
    information. In addition, the government consulted with and retained witnesses
    to analyze the potential effects of the acts alleged in the indictments on Dynegy’s
    and El Paso’s respective profitability.
    Prior to trial, defendants moved to limit or exclude the testimony of two
    government witnesses. Defendants contended that the witnesses were offered
    to present expert testimony, but did not meet the strictures of admissibility. The
    first witness, Glenn Labhart, challenged by Valencia only, was the chief risk
    officer at Dynegy during the time period of the acts alleged in the indictment.
    The government retained Labhart to analyze Dynegy’s monthly positions at the
    time of the acts alleged. Labhart was tasked with determining whether trade
    reports submitted to Inside FERC and NGI contained true or false information,
    whether Dynegy’s monthly positions at certain trading points were long or short,
    and whether changes in the indices published in Inside FERC and NGI would
    have affected Dynegy’s profits. Defendants also moved to limit or exclude the
    testimony of Matthew O’Loughlin. The government retained O’Loughlin in order
    to determine whether Valencia’s and Singleton’s false reports could have, or did,
    affect the monthly indices published by Inside FERC and NGI. The district
    court initially reserved ruling on the admissibility challenges. After a hearing,
    the court held that Labhart was a corporate fact witness presenting analysis
    which was part of his job duties while he was employed at Dynegy.
    6
    No. 08-20546; 08-20573
    Consequently, the court allowed him to testify. The court also conducted a
    hearing to determine whether O’Loughlin’s opinion testimony was admissible.
    The court concluded that his testimony met the admissibility requirements of
    the Federal Rules of Evidence.
    C.
    Trial was held from July 10 to August 4, 2006. Over the course of trial, the
    government presented twenty-one witnesses. The witnesses included natural
    gas traders from Dynegy and El Paso at the time of the acts alleged, corporate
    custodians who testified about the compensation paid to Valencia and Singleton,
    corporate representatives who presented company records from both Dynegy and
    El Paso, the editors of Inside FERC and NGI, and the government’s expert,
    Matthew O’Loughlin. In addition to live testimony, the jury heard dozens of
    phone calls and saw dozens of emails. The jury viewed demonstrative exhibits,
    as well as exemplars of trade tickets from natural gas transactions, and the
    monthly price reports sent by Valencia and Singleton to Inside FERC and NGI.
    Upon completion of the government’s case-in-chief, defendants did not call
    witnesses or present evidence, but rather, moved for judgment of acquittal on all
    counts and rested. The court granted Singleton’s motion as to count six (false
    reporting under the CEA by aiding and abetting) and count ten (obstruction of
    justice). The court denied the motions as to all other counts.
    On August 1, 2006, the court delivered its instructions to the jury, and
    counsel presented closing arguments. The jury then deliberated for several days.
    In a note to the court on August 2, 2006, the jury requested further definitions
    of the terms “price” and “index.” The court referred the jury back to the evidence
    in the case and the court’s instructions. The jury then requested a dictionary.
    The court responded: “No, sorry.” Near the end of the day on August 2, the jury
    stated in a note: “We are currently deadlocked over definitions of price versus
    index as it applies to the fourth element of the false reporting charges. Can we
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    No. 08-20546; 08-20573
    please get further clarification as to their definitions or are they synonymous?”
    The jury also requested the trial transcripts for two witnesses. The court again
    instructed the jury to consider the court’s instructions, the jury’s own
    recollection of the testimony, and the trial exhibits.
    Around noon the next day, August 3, 2006, the jury delivered the court
    another note. It read: “We are deadlocked starting with the first counts and all
    others on the same points as we were all day yesterday as well. We do not agree
    on how the evidence fits the definitions of false reporting and conspiracy and
    neither side is willing to change.” The court brought the jury into the courtroom,
    explained that it was unclear what the jury was struggling with, and asked the
    jury to attempt to resume deliberating after a lunch break. A few hours later,
    the jury sent another note stating: “Following your instructions we took a break
    for lunch in order to clear our heads and give the case a fresh look. After
    returning, we carefully reread your instructions several times and we are still
    hung on the conspiracy count, which we believe to be the foundation of the rest
    of the charges. Specifically for the purpose of this case, we cannot come to an
    agreement on the price of a commodity in relation to the index price. Without
    guidance from the court, we remain hopelessly deadlocked.” In response, the
    court brought the jury into the courtroom. The court provided more overview,
    and instructed the jury to “consider each charge in each indictment separately
    and consider the elements as to each count separately and in light of the rest of
    the charge.” The court asked the jury to continue deliberating.
    At 5p.m. on August 3, the jury sent another note to the court indicating
    that it had reached a verdict on three of the eight counts against Singleton, and
    nine of the twenty-three counts against Valencia. Namely, the note indicated
    that the jury had reached verdicts for the wire fraud counts. However, the jury
    remained “hopelessly deadlocked” over the remaining counts, i.e., the conspiracy
    8
    No. 08-20546; 08-20573
    and CEA counts. The court asked the jury to adjourn for the evening, continue
    thinking about the case, and return in the morning.
    The next morning, August 4, 2006, the jury returned and indicated that
    it wished to continue deliberating. The jury then reached a verdict as to three
    of the CEA counts against Valencia and two of the CEA counts against
    Singleton. At that point, the court took the jury’s partial verdict. The jury found
    Valencia guilty of seven counts of wire fraud, not guilty of two counts of wire
    fraud, and not guilty of three counts of false reporting under the CEA. The jury
    did not reach a verdict as to the remaining ten counts of false reporting or the
    one count of conspiracy. The counts upon which the jury was deadlocked were
    dismissed at the government’s motion. The jury found Singleton guilty of one
    count of wire fraud, not guilty of two counts of wire fraud, and not guilty of two
    counts of false reporting under the CEA. The jury did not reach a verdict as to
    the remaining two counts of false reporting or the one count of conspiracy; these
    were also dismissed at the government’s motion. The district court later denied
    Valencia’s and Singleton’s post-verdict motions for judgment of acquittal and
    motions for a new trial.
    Valencia now argues: (1) that the government committed misconduct by
    reading an incriminating letter aloud during opening statements and referring
    to it again in closing argument, requiring retrial; (2) that the district court
    abused its discretion in allowing Glenn Labhart to testify about the effects of
    Valencia’s actions on Dynegy’s bottom line, and that the government’s at-trial
    disclosure of a fee agreement with Labhart requires a new trial; (3) that the
    district court abused its discretion in allowing Matthew O’Loughlin to testify
    about the effects of false reports on Inside FERC’s and NGI’s indices; (4) that
    cumulative evidentiary errors at trial mandate retrial; (5) that the evidence is
    insufficient to sustain Valencia’s convictions; and (6) that the district court erred
    when sentencing Valencia.        Singleton joins Valencia’s challenges to the
    9
    No. 08-20546; 08-20573
    admissibility of O’Loughlin’s testimony, and challenges the sufficiency of the
    evidence to support the count of wire fraud of which he was convicted.       We
    provide more details herein as they are germane to each issue raised on appeal.
    II.
    We first consider whether the government’s reading of a whistle-blower
    letter by Jeffrey Hornback, a former Dynegy employee, during opening
    statements was reversible plain error. After detailing the circumstances in
    which the government used the letter, as well as Hornback’s in-court testimony,
    we evaluate whether Valencia is entitled to a new trial on this basis. We
    conclude that no reversible error occurred.
    A.
    Following voir dire, the government represented to the court that it would
    not use any trial exhibits during its opening statement. For the most part, the
    government’s hour-long opening statement complied with this representation.
    The prosecutor, Mr. Lewis, gave the jury an overview of natural gas markets, the
    acts alleged, and the means by which the government intended to prove the
    elements of the crimes charged. However, as Mr. Lewis delved into greater
    detail about the specific acts, he showed the jury an excerpt from Government
    Exhibit 14, a price report sent by Singleton to NGI on July 31, 2000. Mr. Lewis
    also described what certain key phone calls would reveal, identifying the
    conversations by date and exhibit number. Defense counsel did not object to the
    use of or reference to these trial exhibits.
    With approximately fifteen minutes left in his allotted time for an opening
    statement, Mr. Lewis told the jury that the government would call Jeffrey
    Hornback as a witness. Hornback was a natural gas trader at Dynegy and a
    coworker of Valencia’s on the West Desk. Mr. Lewis asserted that in July of
    2000, Hornback sent a price report which included fake trades and omitted real
    trades. Hornback allegedly did so at the direction of Valencia and a supervisor
    10
    No. 08-20546; 08-20573
    at Dynegy. Mr. Lewis told the jury: “I’m going to show you evidence that
    employees at Dynegy and El Paso had choices as to what to do when they were
    confronted with opportunities to do something wrong and what I’m going to do
    is read from an exhibit that will, I believe, come into evidence and it’s Exhibit
    668.” The document in question is a letter which Hornback apparently wrote in
    March of 2001, in response to an internal requirement that employees certify
    that they were unaware of violations of Dynegy’s Code of Business Conduct.
    Defense counsel did not object, and the following was read to the jury:
    I am writing this report to expand on the reasons I checked that I
    was aware of violations regarding financial integrity according to
    Dynegy’s Code of Business Conduct. Let me make clear from the
    start that these violations are not in any way related to Dynegy’s
    accounting practices or reporting, but, in my opinion, they are no
    less a violation of integrity than a misstatement of earnings would
    be.
    The first and most widespread problem I have observed is the
    blatant fabrication of numbers reported to the publications that
    report monthly and daily gas price indices. These publications, such
    as Inside FERC, NGI, and Gas Daily, rely on the honesty and
    integrity of companies such as Dynegy to report any and all fixed-
    price physical transactions that actually occur. If transactions are
    actually reported, then the resulting index should always be a fair
    representation of the value of gas at a particular point, at a
    particular time.
    However, at Dynegy I have observed month after month and day
    after day blatant lies being reported by Dynegy to intentionally
    attempt to skew the index in favor of Dynegy’s position. I have seen
    members of top management in the organization instruct traders in
    their group that this is how the game is played and it is how Dynegy
    must behave in order to compete. I have even seen a top manager
    require that he be given a chance to review the numbers before they
    were sent to the publications so he could be sure they were where he
    wanted them to be, regardless of which prices were actually
    transacted.
    To me, it has been a huge ethical dilemma to see volumes reported
    many, many times greater than would have even been possible to
    11
    No. 08-20546; 08-20573
    trade at a given point and to see prices reported well-outside the
    range of what actually traded.
    I know almost every trader and manager at Dynegy condones this
    practice and I know that none of them mean any harm. They are
    only trying to enhance the profitability of their positions.
    Nonetheless, this practice is, in fact, harmful to many outside the
    company. For example, the posted index prices have far-reaching
    impacts, affecting everything from the price utilities pay for their
    gas and ultimately the price that rate payers pay, to the price that
    royalty owners receive for their gas at the wellhead.
    In fact, one of my previous employers was so sensitive to the impact
    that index price reporting had on royalty payments, that the
    company’s traders were forbidden to report to the publications for
    fear of class-action lawsuits.
    Obviously, I am not a legal expert, but I feel very strongly that lying
    on price reports is not only dishonest and unethical, but could
    expose Dynegy to huge legal and public relations risks. It is, after
    all, a blatant form of price manipulation. Imagine how the public
    and press in California would react, for example, if they found out
    that Dynegy’s traders were intentionally manipulating prices higher
    in their state. Consequently, I feel very adamant that Dynegy
    should enact a policy regarding honest reporting to the index
    publications to remove this risk.
    By coming forward with these complaints, I am not trying to get any
    individuals into trouble or cause any dissension in the company. In
    fact, I would not have come forward at all had it not been for the
    code of conduct statements we were forced to sign. I just could not
    with a clean conscience sign that I was unaware of violations
    because of the reasons outlined above.
    I sincerely hope this will remain anonymous and that no individuals
    will be reprimanded. At the same time, it is my true desire that
    these questionable practices should end.1
    Mr. Lewis then told the jury “you will hear that people had choices.” After a few
    more sentences, he concluded his opening statement.
    1
    Because the letter was never subsequently admitted into evidence, its full text was
    not provided to the jury. The foregoing has been reproduced as it appears in the district court’s
    transcript, with minor interjections by Mr. Lewis omitted.
    12
    No. 08-20546; 08-20573
    Mr. Flood, Valencia’s counsel, then began his opening statement. He said:
    “I’m not going to talk about the letter of Mr. Hornback, who’s going to be a
    government witness, because I think the evidence will show that that letter was
    an attempt to try to deflect from his own responsibility in what he had done and
    it has nothing to do with the evidence against Ms. Valencia.” Mr. Flood then
    moved on to other matters.
    Hornback testified at trial for nearly two full days. His live testimony
    described the day-to-day practices of natural gas trading at Dynegy’s West Desk.
    Through Hornback, the government introduced myriad emails, phone calls, and
    other documents. The tone and substance of Hornback’s testimony in many
    ways mirrored the accusations which the prosecutor read to the jury during
    opening statements. For instance, Hornback at one point stated that “as far as
    I can recall, we had never really accurately reported prices.” Rather, when
    Hornback first joined the West Desk, traders would list what they considered
    representative trades, in “an honest attempt to just report what we did see in the
    market.” However, after Dynegy’s West Desk came under the supervision of a
    hard-knuckled vice president named Steve Barron some time in late 1999 or
    early 2000, Dynegy’s reporting practices “became, in my view, an intentional
    attempt to skew the index one way or the other to benefit our positions.”
    Hornback said that there were times where Barron “specifically told me to go
    back and change numbers that I had previously planned to submit.” The change
    in reporting practices was apparently largely driven by a sense that Enron was
    dominating natural gas markets and manipulating prices, and that other players
    in the market had to push back in order to stay afloat.
    Hornback often interacted with Valencia. He stated that in or around July
    of 2000, Dynegy began reporting trades entered into by West Coast LLC (“West
    Coast”). West Coast was a partly owned joint venture of Dynegy and NRG
    Energy, Inc. Hornback testified that Valencia had explained to him that “we
    13
    No. 08-20546; 08-20573
    were going to use [West Coast] to report offsetting transactions to the
    transactions that we submitted at Dynegy to give them basically more validity
    as far as the publication was concerned.” In other words, West Coast would
    report trades with Dynegy at price levels favorable to Dynegy’s market positions
    in an effort to show that greater volumes of gas were being bought and sold at
    a given location. Hornback explained that publications such as Inside FERC and
    NGI might become suspicious if Dynegy alone reported transactions involving
    atypically large volumes of gas, “but if you had two independent parties that
    both had the same data, then the publication would be more likely to believe it
    as being real.”
    Recorded phone calls corroborated the assertion that Valencia participated
    in fabricating trades, inflating the volume of real trades, or omitting real trades
    to favor Dynegy’s positions. With Hornback on the stand, the government
    played a phone call from July 31, 2000, between Valencia and Michael Stewart,
    an employee of West Coast. In the call, Valencia tells Stewart to fax West
    Coast’s price reports to the publications. Valencia states at one point that she
    wants Stewart to fax the data from a separate machine (i.e., a machine in West
    Coast’s office, not Dynegy’s office). Valencia states: “I’m—just worried, I just
    want it to look as legitimate as possible.” In another phone call between Stewart
    and Hornback, also from July 31, 2000, Stewart indicates that “the guy from
    Inside FERC called me about these monthly . . . numbers that Michelle emailed
    him.” Hornback says to Stewart: “these numbers are . . . in the legitimate range,
    so I’m not sure why he would be questioning them.” When asked to explain this
    statement, Hornback testified that “there must have been real trades that
    happened in the ranges of prices that we reported. . . . It seems that they were
    not real trades done at Dynegy though.”
    Additionally, the government introduced a physical trade ticket
    documenting a fixed-price, baseload deal entered into on July 28, 2000, for
    14
    No. 08-20546; 08-20573
    delivery for the next month. Although Hornback filled out the information on
    the ticket, he did so on behalf of Valencia, who had entered into a contract for
    Dynegy to buy 10,000 MMBtu of natural gas from El Paso at a price of $4.60 per
    MMBtu at a delivery point called SoCal Ehrenberg. Hornback agreed that this
    trade met the criteria for reporting to Inside FERC and NGI, but noted that the
    trade was not listed on Dynegy’s monthly report sent on July 31, 2000, from
    Hornback to Kelly Doolan, the chief editor of Inside FERC.
    With Hornback still on the stand, the government demonstrated that
    several other trades meeting Inside FERC’s and NGI’s reporting criteria were
    not in a report sent by Valencia on November 30, 2000. The government played
    a phone call from November 30, 2000, between Valencia and Rick Anderssen, a
    natural gas trader at Pan Canadian Energy Services. Anderssen was Valencia’s
    boyfriend at the time of the call; he is currently Valencia’s husband. In the call,
    Valencia tells Anderssen that she “already turned in my indexes and I couldn’t
    get hold of you because the deadline was one o’clock.” She then tells Anderssen:
    “I turned in twenty thousand at fifteen fifty.” In other words, Valencia reported
    trading 20,000 MMBtu at a price of $15.50. Anderssen states: “I’ll put it down
    right here. Twenty at fifteen fifty. Okay.” Later, Valencia begins to describe
    what she reported for a delivery point in Northern California called Malin.
    Anderssen asks: “Flat to SoCal?” Valencia responds: “F*** no, I want Malin
    low!” Anderssen then asks: “I mean you—you think Malin will be low, yeah. I
    do too.” Valencia answers: “No. I’m only reporting it low.” Hornback testified
    that “flat to SoCal” meant the index price at Malin would be the same as the
    index price at SoCal, or Southern California.
    Hornback testified that at some time during the summer of 2000, he
    overheard Valencia apparently “speaking to a trader at another company
    discussing what prices to report or not report for the first of month index report.”
    He stated that it caused him to become concerned:
    15
    No. 08-20546; 08-20573
    I had been feeling personally conflicted from an ethical standpoint,
    you know, ever since it started to become more of what I felt was a
    dishonest approach to reporting the indices. And that particular
    conversation I remember, you know, it made an impression because
    it kind of scared me a bit, because I remembered enough from
    business law classes in college to know that you shouldn’t be talking
    to somebody at another company about things like that.
    Due to such concerns, some time after overhearing Valencia’s conversation,
    Hornback “decided not to participate anymore with the reporting.”
    I decided that I would report to Michelle what the actual trades
    were that I had transacted and then from there I said that I did not
    want to know anything else about it. Basically I didn’t want to see
    what was sent in, I didn’t want to be a part of any conversations
    about it, kind of just tried to distance myself from it.
    Hornback indicated that Valencia appeared to understand and respect this
    decision. Hornback did not tell Barron about his decision to distance himself
    from the monthly reports.
    After Hornback had been on the stand for several hours, the government
    began a line of questioning concerning Dynegy’s Code of Business Conduct.
    Specifically, in early 2001, employees were required to certify that they knew of
    no ethical violations.   Hornback stated that he could not make such a
    certification in good conscience given what he had witnessed.        Mr. Flood,
    Valencia’s counsel, then requested a sidebar and stated: “During the opening
    statement I unfortunately did not object, I guess. . . . Mr. Lewis read from a
    letter that I think is rank hearsay.” The court noted that the government had
    not offered Hornback’s letter into evidence, and reasoned that the fact that he
    wrote the letter was not hearsay. However, the court continued that if the
    government wished to introduce the letter to prove its contents, i.e., that
    Hornback had witnessed lies being reported to the publications in order to skew
    indices in Dynegy’s favor, there would be a hearsay question. Singleton’s
    counsel, Mr. Nugent, also asserted that the letter was “rank hearsay.” The
    16
    No. 08-20546; 08-20573
    government disagreed. The court stated that it would not admit the letter at
    that time, but would consider admitting portions of it if the need arose.
    Hornback testified that after he declined to certify that he knew of no
    ethical violations, he was contacted by the office of Eric Bruce, Dynegy’s top
    compliance officer.   Hornback met with Bruce, and Bruce requested that
    Hornback describe his observations in a written memorandum. He did so, but
    did not sign or date the document, and left it under Bruce’s door around the
    beginning of March, 2001. When asked why he did this, Hornback said: “I didn’t
    want it to appear that I was trying to betray anybody on the floor, that I was
    trying to get anybody in trouble or anything like that.” Hornback stated that
    Exhibit 668 was a copy of the letter. The government offered the letter into
    evidence; the court stated: “I’m not going to receive it right now.” Some time
    later, Hornback stated that the contents of the writing summarized what he had
    discussed with Bruce concerning misreporting of trades and pressure from
    managers to engage in misconduct. When Hornback could not recall the exact
    contents of the document, the government requested that Hornback be allowed
    to read from it. The court conducted a sidebar at which it ruled that the
    government did not need the document to show that Valencia, like Hornback,
    had a choice as to whether to misreport trade information. Hornback also
    testified that he received a very bad performance review from Steve Barron in
    early 2001. Hornback quit his job at Dynegy in mid-March of 2001, about two
    weeks after delivering the memorandum to Bruce.
    On re-direct examination, Mr. Lewis returned Hornback to his interactions
    with Valencia and other traders on the West Desk regarding the reporting of
    trades. Hornback testified that, on one particular occasion, he had objected to
    efforts to “skew” indices lower because this could reduce royalty payments to
    mineral rights owners, some of whom could be “little old ladies” who depended
    17
    No. 08-20546; 08-20573
    on the royalties for their income. Hornback could not recall whether Valencia
    reacted in any way to this statement.
    Trial proceeded for several more weeks with no references to Hornback’s
    letter. In the first minutes of his closing argument, Mr. Lewis stated: “[T]hese
    index prices were not some sort of theoretical concept floating out there in
    somewhere other than the real world. I mean, people really bought gas at these
    prices. And those little old ladies that Jeff Hornback described, they’re real.”
    Mr. Lewis beseeched the jury to be mindful of Hornback’s testimony. These were
    the only direct references to Hornback made during Mr. Lewis’s closing.
    Thereafter, Mr. Lewis replayed many telephone calls and displayed for the jury
    key documents which had been entered into evidence. He insisted that greed
    motivated the defendants, and not a blind need to follow orders or a desire to act
    as a counterweight to Enron’s perceived dominance of the markets.
    During his closing argument, Mr. Flood repeatedly mentioned Hornback’s
    in-court testimony to show that Valencia was but one of many contributors to the
    monthly price reports, and thus that others were equally or more culpable for
    misrepresentations in the reports. He then stated that he would remind the jury
    of certain things Mr. Lewis said during opening statements:
    “Top management instructed us to report this way. That is how the
    game is played.” Mr. Lewis said that to you in opening statement.
    “Top management changed the numbers on the report. I know that
    every trader and manager at Dynegy condones this practice and I
    know none of them mean any harm.” Those were his words in
    opening statement. “I know none of them mean any harm.”
    Mr. Lewis objected that this line of argument “misstates the opening statement.”
    The court instructed the jury that “it’s up to you to recall Mr. Lewis’s opening.”
    Mr. Flood then moved on, and thereafter made only fleeting references to
    Hornback as a participant in the reporting of false trades.
    Singleton’s counsel, Mr. Nugent, also made references to Hornback’s
    testimony, such as representing that Hornback had said: “We never sent in
    18
    No. 08-20546; 08-20573
    accurate numbers. We sent in representational numbers that were accurate
    market information, but they weren’t based on real trades.” Mr. Nugent later
    said: “But Jeff Hornback finally talks to the vice president of Dynegy, I think his
    name was Eric Bruce, and he talks to him for an hour and [a] half and he writes
    that letter and says, ‘top management is pressuring us at Dynegy.’”
    During rebuttal, Ms. Beek, co-counsel for the government, stated:
    Mr. Flood attributed comments to Mr. Lewis and so did Mr. Nugent
    that were not Mr. Lewis’s. For example, Mr. Lewis read you in the
    opening a whistle-blower letter from Mr. Hornback, where Mr.
    Hornback says, “I am writing this report to expand on the reasons
    I checked that I was aware of violations regarding financial
    integrity according to Dynegy’s code of business conduct.” And then
    he goes on to say, “However, at Dynegy I have observed month after
    month, day after day blatant lies being reported by Dynegy to
    intentionally attempt to skew the index in favor of Dynegy’s
    position. I have seen members of top management in the
    organization instruct traders in their group that this is how the
    game is played and it’s how Dynegy must behave in order to
    compete.” Those were from Mr. Hornback’s whistle-blower letter.
    They were not comments of Mr. Lewis.
    Defense counsel did not object to Ms. Beek’s statements.
    B.
    Valencia says the government should not have read Hornback’s letter
    during the opening statement or read portions of it during the closing argument.
    Valencia says the letter was inculpatory hearsay, and was prejudicial because
    it: (1) described the breadth of the false reporting; (2) divulged the intent and
    identities of the individuals who made false reports; (3) established the
    materiality of the false reports; and (4) suggested what the consequences would
    be. In sum, the letter “established every element of the government’s case and
    was the single most damaging piece of information the jury heard.” Valencia
    insists that the government should have known that the letter might be
    inadmissible, and thus should not have mentioned it until it was admitted.
    19
    No. 08-20546; 08-20573
    Valencia says the letter was not cumulative of Hornback’s in-court testimony,
    as he could not recall all of its contents. The jurors’ difficulty in reaching a
    verdict, and the split verdict it rendered, purportedly militate in favor of a new
    trial. Valencia also argues that the government improperly bolstered its own
    credibility and the credibility of the Hornback letter by stating that it was the
    prosecutor’s job to tell the jury the truth.
    The government stated at oral argument that Valencia’s failure to object
    to use of the letter in advance of trial means she forfeited any challenge to its
    admissibility. In its brief, the government does not actually argue that it was
    proper to read Hornback’s letter during the opening statement, but rather,
    insists that the contents of the letter were never explicitly deemed inadmissible
    hearsay. Moreover, the government says references to the letter during closing
    arguments were invited by defense counsel. The purpose of mentioning the
    letter during closing was, ostensibly, to correct mis-attributions.            The
    government says there is no prejudice because the district court instructed the
    jury that lawyers’ statements and arguments are not evidence.                 More
    importantly, the government says that evidence of Valencia’s and Singleton’s
    guilt was “overwhelming.” The government insists that Hornback’s testimony
    conveyed much of what his letter said, and that Valencia’s own emails and phone
    calls provide ample evidence of guilt.
    C.
    Valencia concedes that she failed to timely object to references to
    Hornback’s letter. We therefore review for plain error. See FED. R. CRIM. P.
    52(b); United States v. Mares, 
    402 F.3d 511
    , 520 (5th Cir. 2005). Valencia must
    show “(1) error, (2) that is plain, and (3) that affects substantial rights.” 
    Mares, 402 F.3d at 520
    (quotation omitted). If these conditions are present, we may
    exercise our discretion to correct the error if it “seriously affects the fairness,
    integrity, or public reputation of judicial proceedings.” 
    Id. 20 No.
    08-20546; 08-20573
    “This court applies a two-step analysis when reviewing claims of
    prosecutorial misconduct. The court must first decide whether the prosecutor
    made an improper remark. The court evaluates the remark in light of the
    context in which it is made.” United States v. Morganfield, 
    501 F.3d 453
    , 467
    (5th Cir. 2007), cert. denied, 
    128 S. Ct. 2500
    (2008) (citations omitted). To
    determine whether improper statements require a new trial, we ask whether the
    prosecutor’s remarks “prejudiced the defendant’s substantive rights,” and “cast[]
    serious doubt on the correctness of the jury’s verdict.” 
    Id. (quotations and
    citations omitted). We must weigh: “(1) the magnitude of the prejudicial effect
    of the prosecutor’s remarks, (2) the efficacy of any cautionary instruction by the
    judge, and (3) the strength of the evidence supporting conviction.” 
    Mares, 402 F.3d at 515-16
    (quotation omitted). We also presume that a jury can and will
    follow an instruction that attorneys’ statements are not evidence, “unless there
    is an overwhelming probability that the jury will be unable to follow the
    instruction and there is a strong probability that the effect is devastating.”
    
    Morganfield, 501 F.3d at 468
    (citations and internal quotations omitted). As for
    “invited error:”
    The doctrine of invited error provides that when injection of
    inadmissible evidence is attributable to the actions of the defense,
    the defense cannot later object to such “invited error.” Under this
    doctrine, a defendant cannot complain on appeal of alleged errors
    which he invited or induced, especially where the defendant may not
    have been prejudiced by the error. We will not reverse on the basis
    of invited error, absent manifest injustice.
    United States v. Green, 
    272 F.3d 748
    , 754 (5th Cir. 2001) (citations and internal
    quotations omitted).
    In United States v. Flores-Chapa, 
    48 F.3d 156
    , 161 (5th Cir. 1995), we
    found that prejudicial prosecutorial comments constituted reversible plain error.
    At trial, the district court ruled that hearsay testimony connecting the defendant
    to a drug conspiracy was inadmissible. 
    Id. at 159.
    However, the government
    21
    No. 08-20546; 08-20573
    referred to the hearsay when examining the next witness and again during
    closing argument. 
    Id. at 159
    & n.6. The court held that the error was plain, and
    that the statement was prejudicial “in the context of the entire trial,” in light of
    the “paucity of evidence” that the defendant was involved in the conspiracy. 
    Id. at 160-61;
    see also United States v. Novak, 
    918 F.2d 107
    , 109 (10th Cir. 1990)
    (noting that a prosecutor may not “refer to evidence of questionable
    admissibility” during opening statements). In Novak, the government made two
    assertions during opening statements which were never substantiated: (1) that
    a citizen reported to police that the defendant sold cocaine from his home; and
    (2) that cocaine seized in the defendant’s home was very pure—“dealer” grade
    as opposed to “user” 
    grade. 918 F.2d at 108
    , 110. The government’s case was
    “completely circumstantial” and relied heavily on inferences drawn from these
    statements to prove the defendant’s intent. 
    Id. at 110-11.
    Therefore, the
    prosecutor’s improper remarks and conduct at trial prejudiced the defendant in
    a way that was incurable by the court’s admonition that the opening statements
    were not evidence. 
    Id. Valencia relies
    primarily on the authority of Flores-
    Chapa and Novak in asserting that the government’s use of Hornback’s letter
    was plain error which prejudiced her substantial rights.
    D.
    We may quickly dispense with the government’s assertion that Valencia
    forfeited the opportunity to challenge the letter’s admissibility by failing to object
    to its use before trial. The district court did set a pre-trial deadline for objections
    to the authenticity of trial exhibits. However, it is abundantly clear, based on
    our review of the record, that the lack of a pre-trial objection did not preclude all
    challenges to the admissibility of an exhibit, as the government suggests. The
    district court regularly entertained objections based on relevance, lack of
    foundation, the hearsay rule, or undue prejudice. The government represented
    in its brief that the court never deemed the letter hearsay. However, prior to
    22
    No. 08-20546; 08-20573
    jury instructions, the government acknowledged that Hornback’s letter was
    never admitted into evidence due to defendants’ hearsay objections. We find the
    government’s insouciance regarding the record and the district court’s orders
    unsettling.
    We conclude that Mr. Lewis’s decision to read Hornback’s letter verbatim
    in his opening statement was improper. See 
    Morganfield, 501 F.3d at 467
    .
    There was a very good chance that the court would deem the letter inadmissible
    hearsay, and the court apparently sustained defendants’ objection to admission
    of the letter for this reason. The government says that the court did not
    explicitly deem the letter hearsay, or alternatively, that the letter could have
    been admitted under the business record exception to the hearsay rule. These
    post-hoc justifications are a thin reed. Mr. Lewis could have simply paraphrased
    Hornback’s anticipated testimony, avoiding the inflammatory language of the
    letter. We admonish the government that its cavalier approach to the district
    court’s rulings has made our task of reviewing the fairness of the trial and the
    soundness of the verdict considerably more difficult.
    The decision to read Hornback’s letter in its entirety was “error.” See
    
    Mares, 402 F.3d at 520
    . However, even assuming the error was “plain,” see 
    id., any prejudice
    to Valencia was minor. The letter does not mention Valencia by
    name. Moreover, over the course of two days, Hornback’s testimony directly
    implicated Valencia in a scheme to mis-state Dynegy’s trades in the monthly
    reports to Inside FERC and NGI. The government presented copious evidence
    of false trade data sent either by Valencia or at her direction. Recordings of
    Valencia’s phone calls provided ample evidence from which the jury could
    conclude that she intended to manipulate the trade reports in order to skew the
    indices in favor of her trading positions, or those of Dynegy as a whole. A
    thorough review of the record refutes Valencia’s contention that Hornback’s trial
    testimony was “vague and ineffective.”      We cannot agree with Valencia’s
    23
    No. 08-20546; 08-20573
    assertion that Hornback’s letter “was the single most damaging piece of
    information the jury heard.” The extensive, incriminating in-court testimony
    provided by Hornback and others, in conjunction with inculpatory, properly
    admitted exhibits, heavily dampened the magnitude of whatever prejudicial
    effect Hornback’s whistle-blower letter had upon the jury. See 
    Morganfield, 501 F.3d at 467
    ; 
    Mares, 402 F.3d at 515-16
    . The judge did not give a cautionary
    instruction to the jury to disregard the contents of Hornback’s letter, but
    Valencia failed to ask for one. Finally, the strength of the evidence supporting
    the wire fraud convictions is strong independent of the assertions in Hornback’s
    letter. See 
    Morganfield, 501 F.3d at 467
    . Therefore, the improper remarks are
    not so prejudicial that a new trial must be held. See id.; 
    Mares, 402 F.3d at 515
    -
    16.
    Valencia relies on Novak and Flores-Chapa, but these cases lend scant
    support to her position. In Novak, the government never presented evidence
    that it had promised in opening statement; references to this “evidence” at trial
    nevertheless played a key role in proving the defendant’s 
    intent. 918 F.2d at 110
    . Here, Hornback’s in-court testimony restated and significantly expanded
    upon the assertions of his letter, and for the first time, implicated Valencia
    personally. This is a far cry from Flores-Chapa, where it was solely inadmissible
    hearsay which connected the defendant to a drug 
    conspiracy. 48 F.3d at 160-61
    .
    What is more, in that case, even after the district court ruled that the evidence
    was inadmissible, the prosecutor made several references to it. In this case, the
    impact of Hornback’s letter was greatly outweighed by his live testimony
    connecting Valencia to the scheme. The district court also never forbade the
    government from making reference to the letter.
    In contrast to opening statements, the government’s references to
    Hornback’s letter during closing arguments were invited. See 
    Green, 272 F.3d at 754
    . Mr. Lewis did not mention the letter during closing argument. Defense
    24
    No. 08-20546; 08-20573
    counsel for both Valencia and Singleton made references to the letter. On
    rebuttal, Ms. Beek clarified who said what. Ms. Beek showed that certain
    statements came from the letter, as opposed to Mr. Lewis. Moreover, the court
    instructed the jury that it was “up to you to recall Mr. Lewis’s opening.” The
    district court later instructed the jury that the lawyers’ arguments and
    statements were not evidence. Valencia shows no reason to disregard our
    normal presumption that the jury is capable of following the court’s instructions.
    See 
    Morganfield, 501 F.3d at 468
    . Having brought up the substance of the
    accusations contained in Hornback’s letter in closing, Valencia cannot contend
    she was prejudiced because the government sought to set the record straight.
    Given these circumstances and the weight of the evidence as a whole, we cannot
    conclude that Ms. Beek’s reference to Hornback’s letter caused “manifest
    injustice.” See 
    Green, 272 F.3d at 754
    .
    Valencia also complains that the government vouched for its own
    credibility and that of Hornback’s letter by stating during closing argument that
    it was the prosecutor’s job to tell the jury the truth. We do not condone such
    statements, but it is implausible to say that this oblique remark, to which
    Valencia did not object and which did not directly bolster the credibility of
    Hornback’s letter, caused devastating prejudice. Cf. United States v. Garcia, 
    522 F.3d 597
    , 601-02 (5th Cir. 2008). The jury’s lengthy deliberations lend support
    to Valencia’s argument that the case was close and the jury struggled to reach
    a verdict. However, the jury was tasked with recalling several weeks worth of
    evidence and deliberating upon more than thirty distinct counts between
    Valencia and Singleton. Also, it is evident from the jury’s notes that it mainly
    struggled to understand the conspiracy and CEA counts, which we do not review
    in this appeal. Given the jury’s difficult assignment, and the panoply of evidence
    supporting guilty verdicts on the wire fraud counts, it would be far-fetched to
    conclude that the mere length of the jury’s deliberations “casts serious doubt on
    25
    No. 08-20546; 08-20573
    the correctness of the jury’s verdict,” rising to the level of plain error. See
    
    Morganfield, 501 F.3d at 467
    (quotation omitted); cf. United States v. Fields, 
    483 F.3d 313
    , 379 (5th Cir. 2007) (Benavides, J., dissenting) (noting that courts “have
    been unwilling to find error harmless where the record . . . affirmatively shows
    that the jurors struggled with their verdict”) (emphasis added).
    We admonish the government that it was improper to read Hornback’s
    letter during opening statement, and that its attempts to justify the error before
    this Court are completely unpersuasive. Nevertheless, considering the entirety
    of Hornback’s testimony in the context of trial, we conclude that references to the
    letter, individually or cumulatively, are not reversible plain error. See 
    Mares, 402 F.3d at 515-16
    .
    III.
    Valencia next raises issues concerning the testimony of Glenn Labhart.
    Valencia makes three distinct arguments: (1) that Labhart was an expert
    witness, implicating the strictures of prior disclosure under Federal Rule of
    Criminal Procedure 16(a)(1)(G), as well as foundation and reliability
    requirements under Federal Rule of Evidence 702; (2) that Labhart provided
    summary testimony which did not comply with Federal Rule of Evidence 1006;
    and (3) that the government’s at-trial disclosure of a fee agreement with Labhart
    was a material violation of Valencia’s rights under Brady v. Maryland, 
    373 U.S. 83
    (1963). Valencia contends that each error is sufficient to require a new trial.
    We first recount the circumstances and details of Labhart’s testimony, and then
    consider each argument in turn. None is meritorious.
    A.
    Glenn Labhart was the chief risk officer of Dynegy from 1997 to 2004. His
    duties included monitoring Dynegy’s trading operations, and specifically,
    26
    No. 08-20546; 08-20573
    enforcing the “trading limits and risk tolerances” set by higher-ups at Dynegy.
    Labhart assisted Dynegy in responding to the government’s requests that
    Dynegy determine whether trades reported by Dynegy and West Coast in 2000
    and 2001 were real or fictitious (“true-false analysis”). He also determined
    whether Dynegy had net long or short positions at various trading points (“long-
    short analysis”). Finally, he analyzed how Dynegy stood to benefit through
    changes in the indices published by Inside FERC and NGI during that time
    period (“penny-up penny-down analysis”). Before trial, Valencia moved to
    exclude Labhart’s proposed testimony on the grounds that it was expert in
    nature, and failed to meet the requirements of Federal Rule of Evidence 702 and
    Daubert v. Merrell Dow Pharmaceuticals, Inc., 
    509 U.S. 579
    (1993). Valencia
    also averred that the government had not provided a report detailing the nature
    of Labhart’s conclusions, and that the government failed to turn over databases
    containing the universe of trade records upon which Labhart based his analysis.
    The district court initially reserved ruling on this motion. On the thirteenth day
    of trial, July 26, 2006, before Labhart had been called to the stand, the court
    conducted a hearing outside of the jury’s presence to evaluate these matters.
    At the hearing, Labhart said he did not complete the true-false, long-short,
    or penny-up penny-down analyses relevant to this case by the time he left
    Dynegy in 2004. He was subpoenaed by the government in March of 2006,
    several months in advance of trial, to pick up where he left off in 2004 and
    complete this work. Labhart was familiar with the trade reports sent to Inside
    FERC and NGI from his time as chief risk officer. He stated that for the true-
    false analysis, trades were reviewed from a system called AREV. AREV was
    generally used to track physical positions for buying, selling, storing, and
    transporting natural gas.     For the long-short and penny-up penny-down
    analyses, Labhart mainly used a risk management system at Dynegy called
    Abacus. Dynegy tracked both physical and financial transactions via Abacus.
    27
    No. 08-20546; 08-20573
    If Labhart needed additional portfolios or records from within the Abacus
    system, he requested the information from Dynegy, which provided it to him.
    A Dynegy computer programmer named Wanda Chovanec assisted Labhart in
    combing through the databases.2 Labhart stated that, just days before he was
    called to testify, he prepared a final summary report of his analysis (“the
    summary report”). The summary report contained positions for each relevant
    month and location at which prices were reported, both physical and financial,
    as contained in Abacus and AREV. Labhart did not show the summary report
    to the government until the day before the July 26 hearing.
    After Labhart stated the foregoing, Valencia’s counsel re-urged the motion
    to exclude Labhart’s testimony on the basis that it was expert testimony, and
    that Labhart had not been shown to be qualified to render such opinions. The
    court overruled the motion as to the true-false and long-short analyses, stating:
    “He’s saying he was reviewing the records and doing exactly what he did while
    he was in the job. He had access to the database as part of his work and he was
    the risk manager.” The court reasoned that such analysis was “clearly what he
    did during the day at work. And the fact that he’s had to reconstruct it later is
    immaterial to the ruling.” However, the court reserved ruling on whether
    Labhart was qualified, based on his job duties while he was at Dynegy, to relate
    the penny-up penny-down analysis to the jury.                   The court ordered the
    government to lay a foundation before seeking to elicit such analysis.
    The government noted that it had provided Labhart with enlargements of
    the monthly price reports sent to Inside FERC and NGI containing the allegedly
    false reports. The government instructed Labhart to mark a blue star next to
    each reported trade which matched an actual fixed-price trade. If the volume
    2
    Chovanec separately testified that she extracted all physical trade information from
    Dynegy’s AREV database. At Hornback’s direction, she conducted searches from the database
    to yield the universe of relevant trades against which Labhart compared the trade reports sent
    by Valencia or at her direction.
    28
    No. 08-20546; 08-20573
    was inaccurate, Labhart was told to write the correct volume in red ink next to
    the reported trade. The government also told Labhart to list omitted reports on
    the report in purple. Finally, Labhart was to include the results of his penny-up
    penny-down analysis, i.e., the amount Dynegy stood to gain or lose from
    movements in a particular index price. The court instructed the government to
    keep the penny-up penny-down figures covered unless and until such analysis
    was deemed admissible. Defense counsel did not object to the use of the marked-
    up reports in this manner.
    With the jury present, Labhart stated that the index prices published by
    Inside FERC and NGI affected Dynegy’s risk positions and profits.
    Consequently, Dynegy vigilantly monitored its positions for locations and
    contracts affected by the published indices. As part of his job as risk manager,
    Labhart could calculate daily how any given trade by the West Desk, or an
    individual trader on the Desk, could affect Dynegy’s profits. Labhart also ran
    profit and loss calculations each month when the index prices were released.
    Labhart stated that he used the same methodology when preparing his penny-up
    penny-down analysis in anticipation of his testimony in this case.
    Outside of the presence of the jury, the court ruled that Labhart’s penny-
    up penny-down analysis was based upon his experience and duties as the chief
    risk officer of Dynegy. The court deemed this “complex lay opinion,” which was
    not expert testimony and therefore was not subject to Federal Rule of Evidence
    702. In the alternative, the court ruled that if Labhart’s opinions were expert
    in nature, such met the requirements of Rule 702. Counsel for Valencia asserted
    that Labhart was a “summary witness,” that no report of Labhart’s opinions was
    given to defense counsel, and moreover, “we have not been able to have his
    methodology and/or his opinions independently assessed by our own expert to
    determine if they’re, in fact, valid.” The court noted that defense counsel had not
    received Labhart’s recent summary report until the day before Labhart testified
    29
    No. 08-20546; 08-20573
    (Labhart put together the report only days before testifying), but “you have had
    the underlying data and could have done this comparison with the databases
    that were provided several weeks ago.”
    With the jury present once more, Labhart first related his true-false
    analysis and long-short analysis. He noted that many of the trades reported by
    Valencia did not exist in the AREV database, that some volumes appeared to
    have been reported inaccurately, and that some real trades meeting the
    reporting criteria were not included. In other words, many of the reports sent
    by Valencia or at her direction contained fictitious or inaccurately reported
    trades, and omitted real trades. Labhart also testified that, based on his review
    of Dynegy’s databases, Valencia often entered into transactions called “swing
    swaps” and “basis swaps,” which used index prices published by Inside FERC
    and NGI. Labhart noted that Valencia often kept “open” positions, meaning her
    monthly natural gas portfolio was either long or short. As a result, changes in
    the published indices would have a direct effect on the performance of Valencia’s
    portfolio.
    Labhart then presented his long-short and penny-up penny-down
    conclusions to the jury. For each report, he indicated how much money Dynegy
    would have gained or lost from a one-cent movement in the indices for each
    trading point, as well as what Dynegy stood to gain from changes in the indices’
    basis figures. Labhart’s true-false and penny-up penny-down analyses were
    depicted on the blow-ups of Dynegy’s monthly reports, which had already been
    admitted into evidence. The jury was thus able to see Labhart’s conclusions
    superimposed on the reports. Defense counsel did not object to the use of reports
    in this fashion, although counsel reiterated objections based upon Labhart’s
    methodology. The true-false, long-short, and penny-up penny-down analysis
    took much of the afternoon of July 26; at the conclusion of this testimony, the
    government passed the witness.
    30
    No. 08-20546; 08-20573
    On the morning of July 27, the government recalled Labhart in order to
    clarify what the markings on the enlarged reports were intended to mean. The
    government then pursued a new line of questioning concerning the time Labhart
    had spent preparing his analysis. Labhart said that after being subpoenaed, he
    spent about 350 hours of his time, for which he had been paid $36,500 by the
    government and about $20,000 by Dynegy. He anticipated billing for additional
    work, for a total of roughly $50,000 from the government. He stated that he was
    not being paid for his in-court testimony. Counsel for Valencia and Singleton
    cross-examined Labhart on the details of his compensation. Counsel protested
    that compensation details had never been disclosed, whereupon the court
    ordered the government to provide such information to defendants.           That
    evening, the government emailed documents including a form number “OBD-47”
    for Labhart, which bears the caption “Expert Witness Statement of Work.”
    Under the heading “Purpose and Objective of Expert Witness Services,” the
    following items are checked:
    (1) To support litigation/prosecution theory or conclusion
    (2) To determine loss dollar value
    (3) To provide technical explanations of fact
    (5) Other: To determine (1) accuracy of reported gas trades & (2)
    benefit to company from changes in index price movement.
    Item (4), “To offer professional opinion,” is not checked. The following items are
    checked under the heading “Preparation and Scope of Work Requested:”
    (1) Review case files, records or evidence
    (3) Create and produce technical charts, graphs or accountings
    (4) Evaluate and compare technical facts
    (6) Validate hypothesis
    (11) Oral presentation to Counsel
    (12) Prepare and present expert reports, graphics, models, exhibits
    and demonstrations for trial preparation and for trial.
    31
    No. 08-20546; 08-20573
    B.
    We agree with the district court’s conclusion that Glenn Labhart was a lay
    witness, and not an expert witness. Labhart’s testimony related to his former
    job duties as risk officer at Dynegy. He recreated much of the analysis he
    regularly performed when evaluating risk tolerances.                       He was properly
    characterized as a fact or lay opinion witness. See FED. R. EVID. 7013; Nat’l
    Hispanic Circus, Inc. v. Rex Trucking, Inc., 
    414 F.3d 546
    , 551-52 (5th Cir. 2005)
    (“Rule 701 does not exclude testimony by corporate officers or business owners
    on matters that relate to their business affairs, such as industry practices and
    pricing.”). Labhart apparently analyzed a great deal of data first provided to
    him after he left Dynegy’s employ. However, this does not change the character
    of his testimony. Valencia insinuates that the timing of Labhart’s departure
    from Dynegy—after the acts complained of but before trial—means his
    testimony must be considered expert in nature. We cannot agree. Because
    Labhart’s knowledge and analysis were derived from duties he held at Dynegy,
    his opinions were admissible as testimony based upon personal knowledge and
    experience gained while employed by Dynegy. See FED. R. EVID. 701. He
    engaged in precisely the kind of analysis he regularly performed as chief risk
    officer; the fact that he drew particular opinions and projection for the purposes
    of this case does not make him an “expert” within the meaning of Federal Rule
    of Evidence 702. See Tex. A&M Research Found. v. Magna Transp., Inc., 
    338 F.3d 394
    , 403 (5th Cir. 2003).4
    3
    “If the witness is not testifying as an expert, the witness’ testimony in the form of
    opinions or inferences is limited to those opinions or inferences which are (a) rationally based
    on the perception of the witness, (b) helpful to a clear understanding of the witness’ testimony
    or the determination of a fact in issue, and (c) not based on scientific, technical, or other
    specialized knowledge within the scope of Rule 702.”
    4
    Valencia cites Teen-Ed, Inc. v. Kimball Int’l, Inc., 
    620 F.2d 399
    , 404 (3d Cir. 1980), for
    the proposition that “[t]he essential difference” between lay and expert testimony “is that a
    qualified expert may answer hypothetical questions.” However, that case holds that “[a]
    32
    No. 08-20546; 08-20573
    C.
    We now turn to Valencia’s argument that Labhart gave inadmissible
    summary testimony. See FED. R. EVID. 1006.5 We review evidentiary rulings for
    an abuse of discretion, and in the event of error, we will affirm provided the
    error is harmless. See United States v. Bishop, 
    264 F.3d 535
    , 546 (5th Cir. 2001).
    While “[r]eview of evidentiary rulings is heightened in a criminal case,” United
    States v. Gutierrez-Farias, 
    294 F.3d 657
    , 662 (5th Cir. 2002), to obtain reversal,
    the appellant “must demonstrate that the district court’s ruling caused [her]
    substantial prejudice.” 
    Bishop, 264 F.3d at 546
    . Here, we may only review for
    plain error because Valencia failed to object to Labhart’s use of the enlarged
    reports to convey his analysis. See FED. R. CRIM. P. 52(b).
    We see no merit in Valencia’s contention that Labhart gave inadmissible
    summary testimony. Labhart’s testimony, and that of programmer Wanda
    Chovanec, indicate that Labhart analyzed all relevant trades contained in
    Dynegy’s vast databases. The government stated at trial that it had provided
    defense counsel with these records approximately one month before trial began.
    Valencia did not dispute that the records had been provided, nor that the
    databases were available for her inspection.6 Valencia provides no support for
    projection of lost profits based on evidence of record regarding decreased sales of a certain
    product may not accurately be characterized as ‘hypothetical.’” 
    Id. Since Labhart
    calculated,
    inter alia, how changes to natural gas indices affected Dynegy’s profits, this case provides little
    support for Valencia. Accord DIJO, Inc. v. Hilton Hotels Corp., 
    351 F.3d 679
    , 686 (5th Cir.
    2003) (noting that “a lay witness who was never employed by or directly involved in a business
    is unlikely to have the type of first-hand knowledge necessary to provide reliable forecasts of
    future lost profits”) (emphasis added).
    5
    “The contents of voluminous writings, recordings, or photographs which cannot
    conveniently be examined in court may be presented in the form of a chart, summary, or
    calculation. The originals, or duplicates, shall be made available for examination or copying,
    or both, by other parties at reasonable time and place. The court may order that they be
    produced in court.”
    6
    The timing of the government’s disclosures is not entirely clear. Following Chovanec’s
    description of the trades she turned over to Dynegy’s counsel, which in turn were provided to
    33
    No. 08-20546; 08-20573
    the statement in her appellate brief that the government “provided the defense
    with disks containing various data splices that had been ‘cherry-picked’ from
    those databases.” At trial, Labhart provided visual depictions of his true-false,
    long-short, and penny-up penny-down analyses, which he was qualified to
    perform based upon his previous experience as chief risk officer. He wrote these
    findings on enlarged copies of the reports sent to Inside FERC and NGI, which
    had been admitted into evidence. In so doing, Labhart was able to compare and
    contrast the false price reports with the financial reality at Dynegy for each
    given month. This would assist the jury in understanding how voluminous
    records boiled down to the potential for profit or loss—a means of showing
    Valencia’s motive for falsifying trade reports. See United States v. Jennings, 
    724 F.2d 436
    , 442 (5th Cir. 1984) (citation omitted) (recognizing that summaries are
    useful to demonstrate the contents of accounts or other business transactions).
    Valencia complains that the government failed to introduce Dynegy’s
    databases into evidence or show that the databases were business records
    subject to a hearsay exception. Valencia cites our decision in Bishop, where we
    noted that “Rule 1006 allows admission of summaries when (1) the evidence
    previously admitted is voluminous, and (2) review by the jury would be
    
    inconvenient.” 264 F.3d at 547
    . Bishop is different because it concerned
    summaries of live testimony and exhibits presented in court, see 
    id., not voluminous
    records which “cannot conveniently be examined in court.” See FED.
    R. EVID. 1006; United States v. Nguyen, 
    504 F.3d 561
    , 571-72 (5th Cir. 2007)
    (citation omitted) (recognizing that Rule 1006 does not concern summaries of
    the government, the government represented that it had turned over the trades to defense
    counsel on January 23, 2006. Defense counsel did not quarrel with this statement. It is
    apparent that counsel was most concerned with whether Chovanec was instructed to search
    all relevant trade records, as well as the completeness of the trades she did search and turn
    over. Nevertheless, in light of Chovanec’s testimony and the government’s uncontested
    representations, we conclude that defense counsel had adequate opportunities to check the
    completeness and veracity of the data relied upon by Labhart.
    34
    No. 08-20546; 08-20573
    trial exhibits or trial testimony). Therefore, despite its broad wording, Bishop
    did not mandate that the databases be admitted into evidence before Labhart
    could summarize their contents, as this would contravene the plain language
    and purposes of Rule 1006. Additionally, Labhart and Chovanec testified that
    Dynegy maintained its databases in the course of regularly conducted business
    activities.   Therefore, the district court did not err, much less abuse its
    discretion, in overruling Valencia’s hearsay-based objections to Labhart’s
    conclusions. See FED. R. EVID. 803(6).
    Valencia was not sandbagged by Labhart’s testimony or reliance on
    records from Dynegy’s AREV and Abacus databases. Counsel cross-examined
    Labhart on the thoroughness and relevance of his calculations, revealing
    familiarity with Dynegy’s use of databases to track its transactions and open
    positions. See 
    Jennings, 724 F.2d at 442
    ; Harris v. United States, 
    356 F.2d 582
    ,
    585 (5th Cir. 1966). In light of the nebulous objections raised by Valencia in the
    trial court—indeed, given her failure to cite Rule 1006 until appeal—we would
    be justified in concluding that an objection based on Rule 1006 was not properly
    raised, and therefore, is forfeited. However, following our independent review
    of the record, we are confident that Labhart’s means of presenting his
    conclusions to the jury was proper.       Valencia has not shown an abuse of
    discretion, much less “substantial prejudice” or plain error mandating a new
    trial. See Bishop, 
    264 F.3d 535
    , 546.
    D.
    We likewise hold that the government’s failure to disclose its fee
    agreement with Labhart was not reversible error. Under the Brady rule, the
    government must give the defense impeachment evidence and exculpatory
    evidence. See United States v. Johnson, 
    872 F.2d 612
    , 619 (5th Cir. 1989). We
    review de novo whether the government violated the Brady rule. United States
    v. Fernandez, 
    559 F.3d 303
    , 319 (5th Cir. 2009). As the proponent of a new trial,
    35
    No. 08-20546; 08-20573
    Valencia must prove that: “(1) the prosecution did not disclose evidence; (2) the
    evidence was favorable to the defense; and (3) the evidence was material.”
    United States v. Infante, 
    404 F.3d 376
    , 386 (5th Cir. 2005). Evidence is material
    if there is a reasonable probability that the outcome of the trial would have been
    different had such evidence been revealed to the defense. 
    Id. “The question
    is
    not whether the defendant would more likely than not have received a different
    verdict with the evidence, but whether in its absence he received a fair trial,
    understood as a trial resulting in a verdict worthy of confidence.” United States
    v. Brown, 
    303 F.3d 582
    , 593 (5th Cir. 2002) (quoting Kyles v. Whitley, 
    514 U.S. 419
    , 434 (1995)). Moreover, the harmless error rule applies to Brady violations.
    
    Id. at 597.7
    In United States v. Cervantes-Pacheco, 
    826 F.2d 310
    , 315-16 (5th Cir.
    1987) (en banc), we reasoned that when the government has a fee arrangement
    with a testifying informant, it must make a “complete and timely disclosure” of
    this to defense. This gives the defendant “an adequate opportunity to cross-
    examine the informant and government agents,” especially if the informant’s
    compensation depends in part on a conviction. See 
    id. at 316.
           The government should have revealed in advance of trial that it had a fee
    agreement with Labhart. Such could have been used to impeach Labhart’s
    motive to tell the truth. However, we conclude that if such failure constituted
    a Brady violation, it was immaterial and harmless. The jury heard that Labhart
    was receiving tens of thousands of dollars from the government and Dynegy in
    exchange for over 350 hours of analysis in this case. He also stated that he was
    subpoenaed to complete work he had not completed while he was employed by
    Dynegy. Labhart was not testifying as an accomplice to a crime seeking a
    7
    Valencia says 
    Kyles, 514 U.S. at 435
    , stands for the proposition that Brady violations
    are never harmless. Kyles actually teaches that a violation of United States v. Bagley, 
    473 U.S. 667
    (1985), is not 
    harmless. 514 U.S. at 435
    . Since a violation of Bagley necessarily entails
    a determination that a Brady violation is material, 
    see 473 U.S. at 678
    , Valencia’s argument
    is off the mark.
    36
    No. 08-20546; 08-20573
    reduced sentence or a “hired gun” in search of a bounty. Rather, Labhart was
    the most qualified person to perform the true-false, long-short, and penny-up
    penny-down analyses. There is no indication that Labhart anticipated receiving
    a bonus in the event of a guilty verdict.       The facts and circumstances of
    Labhart’s unique role in this case do not implicate the policy concerns we have
    expressed about undisclosed payments to informants testifying in criminal cases.
    Cf. 
    Cervantes-Pacheco, 826 F.2d at 315-16
    , overruling Williamson v. United
    States, 
    311 F.2d 441
    , 444 (5th Cir. 1962) (“[W]e cannot sanction a contingent fee
    agreement to produce evidence against particular named defendants as to crimes
    not yet committed.”).
    Valencia asserts that the use of a form commonly used for expert witnesses
    shows the government’s duplicity in hiding the nature of Labhart’s “expert”
    testimony. We cannot agree that the government’s use of a particular form to
    hire Labhart transforms his findings into expert testimony. We reiterate that
    Labhart performed analysis which was part and parcel of his daily duties while
    he was chief risk officer of Dynegy. Valencia also suggests that the boxes
    checked on the contract indicate that Labhart would allow his conclusions to be
    swayed by a “contractual obligation to provide inculpatory, expert testimony at
    trial.” It is true that on the OBD-47 form, the box “support litigation/prosecution
    theory or conclusion” was checked. However, the government had always
    represented that Labhart’s testimony and conclusions would support its theory
    of the case. Ultimately, it is the duty of the jury to determine whether Labhart
    was a credible witness despite his compensation arrangements. See Cervantes-
    
    Pacheco, 826 F.2d at 316
    (“[W]e hold that the credibility of the compensated
    witness, like that of the witness promised a reduced sentence, is for a properly
    instructed jury to determine.”).
    Valencia says advance disclosure of the fee contract would have allowed
    her to more effectively impeach Labhart regarding his pecuniary motives,
    37
    No. 08-20546; 08-20573
    because counsel was focused on numerous other matters in this complex trial.
    Even if this is true, Valencia fails to show that the error was prejudicial—that
    inability to better impeach Labhart rendered her trial unfair. Even without the
    written contract, counsel for both Valencia and Singleton thoroughly cross-
    examined Labhart regarding his fee agreement and insinuated that the
    payments biased him towards the government’s position. See United States v.
    McKinney, 
    758 F.2d 1036
    , 1050 (5th Cir. 1985) (“If the defendant received the
    material in time to put it to effective use at trial, his conviction should not be
    reversed simply because it was not disclosed as early as it might have and,
    indeed, should have been.”). We do not condone the government’s failure to
    reveal in advance its compensation agreement with Labhart. However, this
    misstep does not undermine confidence in the jury’s verdict. See 
    Infante, 404 F.3d at 386
    ; 
    Brown, 303 F.3d at 593
    , 597. Valencia is not entitled to a new trial
    on this basis.
    IV.
    The next issue on appeal, urged by both Valencia and Singleton, concerns
    the testimony of the government’s expert, Matthew O’Loughlin. Defendants
    contend that the district court abused its discretion in admitting O’Loughlin’s
    testimony, which fell short of the admissibility requirements of expert opinions.
    We disagree.
    A.
    The government hired O’Loughlin to evaluate whether defendants’ false
    reports affected or tended to affect the natural gas indices published by Inside
    FERC and NGI. On July 5, 2006, days before trial began, defendants requested
    a hearing regarding expert testimony; on July 8, 2006, defendants moved to
    exclude O’Loughlin’s testimony as unreliable under Federal Rule of Evidence
    702 and Daubert. At a pretrial hearing, the court stated that the motion to
    exclude was untimely, but indicated that it would entertain the objection
    38
    No. 08-20546; 08-20573
    pursuant to its gatekeeping duty. Several days into trial, on July 14, 2006, the
    district court held a conference outside of the presence of the jury, at which it
    considered the admissibility of O’Loughlin’s testimony. O’Loughlin was not
    present, but the court considered the report he had prepared pursuant to
    Federal Rule of Criminal Procedure 16, as well as counsel’s arguments. The
    court explained that the purpose of the conference was to determine whether
    O’Loughlin’s presence at a Daubert hearing would be necessary, or whether the
    court could make admissibility determinations based on information already
    available.
    It was undisputed that indices published by Inside FERC and NGI were
    commonly used by participants in natural gas markets to price transactions.
    However, defendants contested whether false reports could have an effect on the
    published indices. Legally, this was relevant to the materiality of the reports for
    both the CEA and the wire fraud counts. At first blush, the relationship between
    price reports and indices would seem elementary: the editors of both Inside
    FERC and NGI testified that the reports were their starting point when
    determining index prices. However, neither editor could say that a given report
    could, or actually did, change the index price. Specifically, Kelly Doolan, chief
    editor of Inside FERC, testified that he examined the volume-weighted averages
    for bidweek trades. However, he said he exercised his judgment in determining
    whether to include all reported trades in the averages. Doolan frequently
    discarded what he considered outlier data, and said it “would be speculation” to
    conclude that a particular report had changed, or could change, the indices. He
    might also decide to alter an index price based on information not contained in
    the price reports. Mark Curran, chief editor of NGI, examined the trade reports
    and used editorial discretion in determining whether to include all trades in the
    volume-weighted average. However, Curran testified that, after deciding which
    39
    No. 08-20546; 08-20573
    figures to include or exclude, he typically published the final volume-weighted
    averages as NGI’s index prices.
    In light of the assertions of Doolan and Curran regarding their editorial
    discretion in creating the monthly indices, the government could not simply ask
    the jury to infer or assume that a given false price report had changed, or had
    the tendency or ability to change, a given index price. The government retained
    O’Loughlin in order to probe the relationship of the price reports to the indices.
    O’Loughlin was provided the trade reports submitted to Inside FERC. He
    calculated volume-weighted averages for all reported trades and delivery nodes,
    and compared these figures to Inside FERC’s published index prices. In this
    manner he could test how closely the indices tracked the raw data. For NGI, the
    monthly reports were not available. However, O’Loughlin was able to obtain the
    final worksheets used by chief editor Mark Curran to calculate the publication’s
    volume-weighted averages, which ultimately became the index prices. For both
    Inside FERC and NGI, O’Loughlin found a strong correlation between the
    volume-weighted averages of the trades submitted and the published index
    prices. O’Loughlin then examined the months when Valencia or Singleton
    allegedly submitted false reports. He removed the false trades in an effort to see
    whether the trades had the potential to change the volume-weighted averages.
    He found that they did.
    At the July 14 conference, the court acknowledged that O’Loughlin’s
    methodology was “not one that he purports others have used,” and that he was
    “largely summarizing factual material and then doing an arithmetic calculation.”
    However, the court also reasoned that this issue was res nova, as “there has been
    no need in the world for anyone to do the work that O’Loughlin has done.” The
    upshot of O’Loughlin’s analysis was, as the district court stated, an inference
    that Inside FERC’s and NGI’s published indices closely tracked the volume-
    weighted averages of the trades submitted to the publications. Thus, the
    40
    No. 08-20546; 08-20573
    editorial judgment of the editors was minimal. Defense counsel objected that
    O’Loughlin would essentially be asking the jury to disregard the editors’
    testimony. Moreover, Doolan and Curran exercised discretion in deciding which
    trades to include or exclude from the volume-weighted averages. Therefore,
    defendants asserted that O’Loughlin failed to account for a critical step in the
    process of creating the indices. The court ruled that this did not undermine
    O’Loughlin’s methodology, but instead challenged an assumption he made in
    reaching his conclusions. The court reasoned that defendants’ critiques affected
    the weight of the testimony, not its admissibility, and were fodder for cross-
    examination. Consequently, the court held that the government had met its
    burden of proving under Daubert that the expert’s methodology and opinions
    were reliable, and were based on sufficient data.
    O’Loughlin testified near the end of trial, from July 27 to 28, 2006.8 He
    stated that, in order to analyze Inside FERC’s practices, he examined the trade
    reports for a twenty-eight month period from January 2000 through April 2002.
    These reports were used to create approximately 1,600 index prices for various
    trading points. He used the reports to create a volume-weighted average for
    each point. O’Loughlin found that for the vast majority of the data points,
    approximately eighty percent, the volume-weighted average was the same as the
    published index price. The data points were depicted on a graph and displayed
    to the jury. Based on these observations, O’Loughlin opined that the volume-
    8
    Prior to O’Loughlin’s in-court testimony, Valencia’s counsel re-urged the motion to
    exclude on the basis that O’Loughlin made unfounded assumptions when forming his opinions,
    namely that the volume-weighted averages became the index prices. The court stated: “As I
    understand O’Loughlin’s testimony, he will do statistical analysis to the effect that the vast
    majority of time the volume-weighted average is the index price.” The court stated that it had
    seen O’Loughlin’s “statistical analysis, and there is a very strong correlation between the
    volume-weighted average and the index price” for both Inside FERC and NGI. Thus,
    O’Loughlin could testify about the correlation, and defendants’ objections concerned the weight
    of his testimony in the mind of the jury, not its admissibility. The court added, however, that
    without a proper foundation, it would not allow O’Loughlin to opine about whether, if the false
    “trades had not been included in the data the index would have changed.”
    41
    No. 08-20546; 08-20573
    weighted average “has a strong relationship with the index price,” and that a
    change in the volume-weighted average was “very likely to lead to a different
    index price.” In light of the frequency with which the volume-weighted average
    and the index price were very close or identical, he inferred that the volume-
    weighted average was “an explanatory variable for the index price.” He further
    explained that, in light of the data, it appeared that there was a relationship
    between the volume-weighted averages and the index prices, “and the
    relationship is showing that the change in the volume-weighted average appears
    to be one for one with the change in the index price.”
    O’Loughlin reached a similar conclusion for NGI. Although he lacked the
    bidweek data submitted to NGI, O’Loughlin read from NGI’s methodology
    statement, which stated: “The prices that appear in NGI’s gas price index
    represent the volumetric weighted average of negotiated fixed price transactions
    that occur during a particular time period . . . .” As O’Loughlin explained, the
    methodology statement acknowledged that outlier data would be discarded, and
    that the volume-weighted average of the remaining data set would be published
    as the index price. On this basis, he concluded that the volume-weighted
    average was the most important component of NGI’s indices.
    In addition, O’Loughlin testified about whether the false trades submitted
    by defendants had the potential to change the volume-weighted averages
    compiled by Inside FERC and NGI. In the case of trades submitted by Valencia
    to Inside FERC and identified by Glenn Labhart as false, O’Loughlin found that
    removing the trades could change the volume-weighted averages, in some cases
    by several cents. O’Loughlin engaged in this analysis for the false trades
    submitted to NGI by both Valencia and Singleton, and concluded that these also
    had the potential or tendency to affect the volume-weighed averages. Finally,
    O’Loughlin drew the inference that because volume-weighted averages were the
    most important component of the indices, and because trade reports had the
    42
    No. 08-20546; 08-20573
    potential to affect volume-weighted averages, false trade reports had the
    tendency or capability to affect the final published index prices. In particular,
    O’Loughlin noted that, based upon his review of Curran’s testimony, most trades
    submitted by Dynegy and El Paso would be included in the volume-weighted
    averages, and hence, the indices. His conclusion covered both Inside FERC and
    NGI: “[G]iven that there is this relationship that we’ve seen both for Inside
    FERC and NGI between changes in the volume-weighted average and changes
    in the index price, my sense is that if, in fact, the volume-weighted average is
    being affected by more than a penny, it is likely that there was some influence
    on the index price.”
    B.
    Valencia and Singleton argue that the district court abused its discretion
    in admitting O’Loughlin’s opinions. Defendants do not contest his credentials
    or qualifications, but rather, argue that his testimony was not relevant or
    reliable. Defendants fault the district court for failing to require that O’Loughlin
    be present for voir dire at a pre-trial Daubert hearing, and for ruling on the
    admissibility of his opinions mid-trial. Defendants say the court abdicated its
    gatekeeping role over expert testimony, and allowed spurious testimony to reach
    the trier of fact. Defendants criticize O’Loughlin’s calculations as unreliable
    tweaks to volume-weighted averages, which disregarded Doolan’s and Curran’s
    testimony that their respective indices “were determined through subjective
    editorial judgments.” As such, defendants characterize O’Loughlin’s conclusions
    as impermissible attacks on the witnesses’ credibility.           Defendants say
    O’Loughlin’s analysis was unreliable because he did not conduct multiple-
    regression analysis to account for potentially confounding variables affecting the
    index prices. On this basis, O’Loughlin allegedly posited an unsubstantiated
    causal link between the defendants’ false reports and changes in the published
    indices. Defendants say the admission of the testimony prejudiced them because
    43
    No. 08-20546; 08-20573
    the aura of credibility conferred by O’Loughlin’s expert status likely swayed the
    jury to find the materiality element of the crimes, which no other evidence in the
    record directly provided.
    Moreover, Valencia contends that O’Loughlin wrongly conveyed hearsay
    directly to the jury. O’Loughlin evaluated so-called voice broker data generated
    by services such as the now-defunct Enron Online, which matched buyers and
    sellers of gas. After evaluating these records, O’Loughlin testified that Dynegy
    used Inside FERC’s indices in California to price gas contracts.             This
    contradicted Jeffrey Hornback’s testimony that Dynegy used NGI’s indices to
    price contracts in California. O’Loughlin allegedly failed to state in his expert
    report that he would consider voice broker data or present this conclusion.
    Singleton argues separately that O’Loughlin wrongly concluded that Singleton’s
    July 31, 2000 email to NGI “likely” influenced NGI’s Southern California Border
    index. However, Singleton says that the volume-weighted average for Curran’s
    worksheets for that month remains the same whether Singleton’s trades are
    included or excluded. Singleton says this erroneous statement indicates that
    O’Loughlin’s opinions are unreliable.
    The government says O’Loughlin was qualified to testify as an expert in
    the fields of economics and energy affairs with experience evaluating natural gas
    indices. Moreover, his analysis conforms to the requirements of relevance and
    analytical rigor required of an expert in economics or statistics. The government
    contends that multiple regression analysis was not necessary because
    O’Loughlin was trying to establish that, notwithstanding the editorial judgment
    exercised by the editors of Inside FERC and NGI, defendants’ false reports had
    the potential or tendency to influence index prices. The government also states
    that defendants did not criticize the lack of regression analysis during voir dire
    of the witness or before the district court. Because success of a scheme is not an
    element of wire fraud, the government says it was proper to allow O’Loughlin to
    44
    No. 08-20546; 08-20573
    testify that it was possible or likely that the false reports were market-moving
    communications without eliminating all confounding or contributory factors.
    C.
    We review the admission or exclusion of expert testimony for an abuse of
    discretion. Kumho Tire Co. v. Carmichael, 
    526 U.S. 137
    , 152 (1999). The district
    court’s ruling will not be disturbed on appeal unless it is manifestly erroneous.
    United States v. Norris, 
    217 F.3d 262
    , 268 (5th Cir. 2000). If the court abuses its
    discretion, judgment will be affirmed under the harmless error doctrine unless
    the error affected a substantial right of the defendant. 
    Id. (citations omitted);
    Watkins v. Telsmith, Inc., 
    121 F.3d 984
    , 988 (5th Cir. 1997) (noting that
    “[d]istrict courts enjoy wide latitude in determining the admissibility of expert
    testimony”) (citations and internal quotations omitted).
    Under Federal Rule of Evidence 702,9 district courts are assigned a
    gatekeeping role to determine the admissibility of expert testimony. 
    Daubert, 509 U.S. at 592-93
    . The court must find that the evidence is both relevant and
    reliable before it may be admitted. 
    Id. To do
    so, the court must evaluate
    whether the reasoning and methodology underlying the testimony is valid and
    can be reliably applied to the facts of the case. 
    Id. This requires
    more than a
    glance at the expert’s credentials; the court must also ensure that the expert has
    reliably applied the methods in question. See Moore v. Ashland Chem. Inc., 
    151 F.3d 269
    , 276 (5th Cir. 1998) (en banc). Factors to consider when evaluating
    reliability include: (1) whether a theory or technique can be tested; (2) whether
    the theory or technique has been subjected to peer review and publication; (3)
    9
    “If scientific, technical, or other specialized knowledge will assist the trier of fact to
    understand the evidence or to determine a fact in issue, a witness qualified as an expert by
    knowledge, skill, experience, training, or education, may testify thereto in the form of an
    opinion or otherwise, if (1) the testimony is based upon sufficient facts or data, (2) the
    testimony is the product of reliable principles and methods, and (3) the witness has applied the
    principles and methods reliably to the facts of the case.”
    45
    No. 08-20546; 08-20573
    the known or potential rate of error; (4) the existence and maintenance of
    standards and controls; and (5) general acceptance of the theory in the scientific
    or expert community. 
    Daubert, 509 U.S. at 593-95
    . Nevertheless, the reliability
    inquiry is flexible, and the judge has discretion in determining which factors are
    most germane in light of the nature of the issue, the particular expertise, and
    the subject of the expert’s testimony. 
    Id. at 594-95;
    Kumho 
    Tire, 526 U.S. at 142
    .
    Overall, the trial court must strive to ensure that the expert, “whether basing
    testimony on professional studies or personal experience, employs in the
    courtroom the same level of intellectual rigor that characterizes the practice of
    an expert in the relevant field.” Kumho 
    Tire, 526 U.S. at 152
    .
    The relevance and reliability of expert testimony turns upon its nature and
    the purpose for which its proponent offers it. See, e.g., Hodges v. Mack Trucks,
    Inc., 
    474 F.3d 188
    , 195 (5th Cir. 2006) (“Of course, whether a proposed expert
    should be permitted to testify is case, and fact, specific.”) (citing Kumho 
    Tire, 526 U.S. at 150-51
    ). Expert statistical opinions are often offered to demonstrate a
    causative relationship between a dependent variable and an explanatory
    variable because the existence vel non of a causal link is a legally relevant fact
    of consequence.10 See, e.g., Munoz v. Orr, 
    200 F.3d 291
    , 300 (5th Cir. 2000) (in
    Title VII disparate impact claim, “the evidence will focus on the degree of
    statistical disparity between protected and non-protected workers in regards to
    employment or promotion”); Sheehan v. Daily Racing Form, Inc., 
    104 F.3d 940
    ,
    942 (7th Cir. 1997) (Posner, J.) (in age discrimination claim, “equating a simple
    statistical correlation to a causal relation . . . indicates a failure to exercise the
    degree of care that a statistician would use in his scientific work”); McClain v.
    Metabolife Int’l, Inc., 
    401 F.3d 1233
    , 1243 (11th Cir. 2005) (in claims for toxic
    10
    See FED. R. EVID. 401 (“‘Relevant evidence’ means evidence having any tendency to
    make the existence of any fact that is of consequence to the determination of the action more
    probable or less probable than it would be without the evidence.”).
    46
    No. 08-20546; 08-20573
    torts or negligent prescription, evidence of correlation or temporal proximity
    cannot establish required causative nexus between defendant’s act and plaintiff’s
    ensuing injury). Logically and legally speaking, in such cases causal evidence
    is relevant to the jury. See Huss v. Gayden, 
    571 F.3d 442
    , 457 (5th Cir. 2009)
    (noting, in dictum, that evidence of injury by negligent prescription must be
    shown “to a reasonable degree of medical certainty”) (citation omitted), petition
    for cert. filed, 
    78 U.S.L.W. 3447
    (U.S. Jan. 8, 2010) (No. 09-842).
    Evidence of mere correlation, even a strong correlation, is often spurious
    and misleading when masqueraded as causal evidence, because it does not
    adequately account for other contributory variables. See, e.g., 
    id. at 459
    (“Any
    scientist or statistician must acknowledge, however, that correlation is not
    causation.”); 
    Munoz, 200 F.3d at 301-02
    ; 
    Sheehan, 104 F.3d at 942
    (“Completely
    ignored was the more than remote possibility that age was correlated with a
    legitimate job-related qualification, such as familiarity with computers.”).
    However where evidence of correlation itself is potentially relevant and unlikely
    to mislead the jury, an expert who reliably discerns this relationship can present
    such conclusions to the jury. See Pirlott v. NLRB, 
    522 F.3d 423
    , 435, 436 (D.C.
    Cir. 2008) (reasoning that, in order to charge objecting nonmembers union dues,
    union can show “a positive correlation between wages and union density in the
    relevant market at issue”; expert witness presented such evidence) (internal
    quotation and citation omitted); United States v. W.R. Grace, 
    504 F.3d 745
    , 765
    (9th Cir. 2007) (holding that “the fact that a study is associational—rather than
    an epidemiological study intended to show causation—does not bar it from being
    used to inform an expert’s opinion about the dangers of asbestos releases”);
    United States v. White, 
    356 F.3d 865
    , 870 (8th Cir. 2004) (“Our court recognizes
    the known correlation between drug dealing and weapons, and accepts that they
    are closely and integrally related to the issue of possession of a firearm.”); United
    States v. Hopkins, 
    310 F.3d 145
    , 151 (4th Cir. 2002) (holding that expert
    47
    No. 08-20546; 08-20573
    testimony that defendant’s behavior was consistent with dealing crack was
    relevant and reliable in light of expert’s law enforcement experience and
    analysis of germane facts in the case). Whether a particular opinion is relevant
    and reliable thus does not simply turn on whether the expert asserts a causal or
    correlative relationship, but is closely tied to the law and facts at issue in a given
    case. See 
    Hodges, 474 F.3d at 195
    .
    D.
    Having reviewed the parties’ arguments, O’Loughlin’s testimony, and the
    district court’s thorough examination of the proffered opinions, we cannot
    conclude that the court abused its discretion and committed manifest error in
    allowing O’Loughlin to testify about the tendency of defendants’ false trade
    reports to affect the indices published by Inside FERC and NGI.
    Regarding the Daubert factors, the district court recognized that the
    unprecedented nature of O’Loughlin’s work made it impractical, if not
    impossible, to subject the methods to peer review and publication, and that there
    would be no general acceptance of the theory in the scientific or expert
    community. 
    See 509 U.S. at 593
    (noting that publication “is not the sine qua non
    of admissibility; it does not necessarily correlate with reliability, and in some
    instances well-grounded but innovative theories will not have been published”)
    (internal citations omitted). However, given the arithmetic underpinnings of
    O’Loughlin’s analysis, one can test the theories and determine the rate of error.
    See 
    id. Indeed, by
    noting that the volume-weighted averages matched the
    published indices approximately eighty percent of the time, O’Loughlin
    acknowledged that his opinion—that prices reports had the tendency to affect
    indices—was imperfect. The district court recognized that the fit between the
    data and O’Loughlin’s theory was approximate, but reasoned this did not render
    the opinions altogether unreliable, and defendants could highlight any
    inconsistencies on cross-examination. In light of the district court’s insightful
    48
    No. 08-20546; 08-20573
    consideration of, and fidelity to, the Daubert factors at this necessarily “flexible”
    stage of the trial, see 
    id., we cannot
    say that the court abused its discretion in
    admitting O’Loughlin’s testimony as sufficiently rigorous economic and
    statistical analysis. The record belies defendants’ assertion that the court
    abdicated its duty to exclude irrelevant or spurious testimony from the
    courtroom. Moreover, the court did not abuse its discretion in declining to
    require that O’Loughlin be present at the Daubert hearing, especially in light of
    defendants’ eleventh-hour motion to exclude his testimony.
    Concerning relevance, it is important to bear in mind that in this case,
    defendants were charged with, and we now review convictions solely based upon,
    wire fraud. To prove wire fraud, the government must show a scheme to
    defraud, the use of wire communications in furtherance of the scheme, and the
    defendant’s specific intent to participate in the scheme.                 United States v.
    Stalnaker, 
    571 F.3d 428
    , 436 (5th Cir. 2009) (citations omitted). The government
    must also prove that the communications were material. Neder v. United States,
    
    527 U.S. 1
    , 25 (1999). A “material” statement has “a natural tendency to
    influence, or is capable of influencing, the decision of the decision-making body
    to which it was addressed.” See United States v. Lucas, 
    516 F.3d 316
    , 339 (5th
    Cir.) (quotation omitted), cert. denied, 
    129 S. Ct. 116
    (2008)11; United States v.
    Philip Morris USA Inc., 
    566 F.3d 1095
    , 1122 (D.C. Cir. 2009) (“This materiality
    requirement is met if the matter at issue is of importance to a reasonable person
    in making a decision about a particular matter or transaction.”) (citation and
    internal quotation omitted).         Success of the scheme is not an element of the
    crime. See United States v. Loney, 
    959 F.2d 1332
    , 1337 (5th Cir. 1992).
    11
    Lucas is a mail fraud case, but the same analysis and reasoning applies to wire fraud.
    See United States v. Mills, 
    199 F.3d 184
    , 188 (5th Cir. 1999); see also 
    Neder, 527 U.S. at 25
    (“[W]e hold that materiality of falsehood is an element of the federal mail fraud, wire fraud,
    and bank fraud statutes.”).
    49
    No. 08-20546; 08-20573
    Defendants agree that O’Loughlin’s testimony concerned the materiality
    of defendants’ false reports.    For this element, it was incumbent on the
    government to show that the false reports had the tendency to influence the
    indices published by Inside FERC and NGI. It was not legally determinative
    whether a particular report actually changed a particular index price.
    O’Loughlin concluded, after evaluating the relationship between the data and
    the indices, that the information submitted by Valencia and Singleton, or at
    their direction, would be important to a reasonable person seeking to determine
    the price of natural gas at the trading points for which defendants submitted
    reports. This inference is largely consistent with the testimony of Doolan and
    Curran, who said they considered the bidweek reports when creating index
    prices. While it was a matter of editorial discretion whether a given trade would
    be included within a volume-weighted average, and ultimately, the index price,
    O’Loughlin demonstrated that this discretion was either infrequently invoked
    or played a comparatively minor role.
    We acknowledge that O’Loughlin’s conclusions were somewhat in tension
    with the statements of Doolan and Curran. However, O’Loughlin did not simply
    urge the jury to disregard their testimony. O’Loughlin’s conclusion was well
    grounded in his thorough analysis of the data, not a metaphysical disagreement
    with the editors’ assertions. We therefore reject defendants’ argument that
    O’Loughlin’s opinion was an unsubstantiated and impermissible attack on the
    editors’ credibility.   Because O’Loughlin’s testimony helped show that the
    bidweek reports were important to Doolan and Curran, the testimony was
    relevant to the element of materiality. See Philip 
    Morris, 566 F.3d at 1123
    (“The
    question, however, is not whether a reasonable person would have believed
    Defendants’ false statements, but only whether a reasonable person would have
    considered the issue of importance . . . .”) (quotation marks omitted).
    50
    No. 08-20546; 08-20573
    As for reliability, O’Loughlin carefully explained the nature of his
    conclusions so that he remained within the scope of his properly admitted
    opinions. Contrary to defendants’ representations, O’Loughlin did not state that
    the false reports changed the published indices. Rather, he stated that volume-
    weighted averages and index prices often moved in tandem, and that volume-
    weighted averages were an “explanatory variable” for index prices. Based upon
    this observation, it was possible, or in some cases, likely that the false reports
    would have an effect on the volume-weighed averages, and hence, the indices.
    The statements cited by defendants as evidence of unsubstantiated causation
    testimony are either couched in terms of changes to volume-weighted averages
    or are answers to hypothetical questions. In isolated instances, O’Loughlin
    stated that false reports changed the indices. However, if counsel objected, the
    district court sustained the objection, and O’Loughlin then corrected himself.
    Such slip-ups are not prejudicial in light of the fact that O’Loughlin meticulously
    maintained the distinction between volume-weighted averages and final index
    prices. Moreover, on cross-examination, O’Loughlin stated that he did not
    assume, nor conclude after his analysis, that any one-cent change in a volume-
    weighted average would lead to a corresponding one-cent change in an index
    price. Therefore, O’Loughlin’s opinions were both relevant and reliable.
    We disagree with defendants’ assertion that the testimony should have
    been excluded because O’Loughlin did not employ multiple regression analysis.
    Multiple regression analysis is a tool for understanding the relationship between
    a dependent and an explanatory variable. See generally Daniel L. Rubinfeld,
    Reference Guide on Multiple Regression, in REFERENCE MANUAL ON SCIENTIFIC
    EVIDENCE 179 (2d ed. 2000). Defendants are correct to point out that this is a
    powerful tool when the trier of fact must determine whether a causal link exists.
    Nevertheless, regression analysis is not a mandatory feature in all applications
    of economics or statistics. See Adams v. Ameritech Servs., Inc., 
    231 F.3d 414
    , 425
    51
    No. 08-20546; 08-20573
    (7th Cir. 2000) (“[W]e are not prepared to hold as a matter of law that nothing
    but regression analyses can produce evidence that passes the Daubert and
    Kumho Tire thresholds. Statisticians might have good reasons to look at data
    in different ways.”).
    In cases where a causal relationship is not an essential fact of
    consequence, an expert need not eliminate all confounding variables or potential
    contributory factors in order to present an opinion that is both relevant and
    reliable. See Int’l Bhd. of Teamsters v. United States, 
    431 U.S. 324
    , 340 (1977)
    (noting that the usefulness of statistics “depends on all of the surrounding facts
    and circumstances”); cf. Mathis v. Exxon Corp., 
    302 F.3d 448
    , 461 (5th Cir. 2002)
    (“Although Pulliam may not have isolated the precise effect Exxon’s pricing had
    on each station, that was not the purpose of his testimony. The ‘subject of his
    testimony,’ as listed by plaintiffs, was whether Exxon had set a commercially
    reasonable price in an economic sense.”). In this case, to show that defendants’
    statements were material, the government had to prove that they were
    important to Doolan and Curran, not that the statements caused Doolan and
    Curran to change the indices. See Philip 
    Morris, 566 F.3d at 1123
    . O’Loughlin
    reached his conclusions after applying statistical methods in a reliable manner.
    In this case, the lack of regression analysis affected the weight which the jury
    assigned to the expert’s testimony, not its legal admissibility.
    Valencia also contends that O’Loughlin relied on inadmissible hearsay to
    fill a “gap” in the government’s case. Specifically, Jeffrey Hornback testified that
    Dynegy used NGI’s indices to price California contracts. O’Loughlin relied on
    voice broker records to show that Dynegy also used Inside FERC’s indices.
    Valencia says this is significant because the false reports she sent were mostly
    directed to Inside FERC. Valencia complains that O’Loughlin did not disclose
    in his Rule 16 report that he would rely on voice broker data, and that
    O’Loughlin directly conveyed inadmissible documents to the jury. At trial, the
    52
    No. 08-20546; 08-20573
    district court overruled Valencia’s hearsay-based objections to Government
    Exhibit 686, which purported to show, inter alia, that Dynegy used Inside
    FERC’s indices for contracts in California.12
    We do not believe that the court abused its discretion in allowing
    O’Loughlin to present this conclusion to the jury. O’Loughlin did not directly
    convey voice broker data to the jury. Rather, he analyzed the data, concluded
    that Dynegy used Inside FERC’s indices to price transactions, and conveyed this
    conclusion to the jury in the form of an exhibit he created. Valencia has not
    shown that the court abused its discretion in treating the voice broker data as
    business records, nor that the court erred in holding that O’Loughlin was
    entitled to rely on the records in forming his expert opinion. See FED. R. EVID.
    703 (“If of a type reasonably relied upon by experts in the particular field in
    forming opinions or inferences upon the subject, the facts or data need not be
    admissible in evidence in order for the opinion or inference to be admitted.”);
    United States v. Avants, 
    367 F.3d 433
    , 447 (5th Cir. 2004). Because Valencia did
    not object at trial that the testimony was beyond the scope of O’Loughlin’s Rule
    16 expert report, we may only review for plain error. See 
    Avants, 367 F.3d at 446
    . Government Exhibit 431, a Dynegy contract using an Inside FERC index
    to price a gas transaction in California, was submitted into evidence without
    objection. Because independent evidence corroborates O’Loughlin’s conclusions,
    Valencia’s substantial rights were not affected. See 
    Mares, 402 F.3d at 520
    .
    Singleton maintains that O’Loughlin’s materiality opinion is inadmissible
    because the report Singleton submitted on July 31, 2000 could not have changed
    12
    Valencia never objected at trial that the voice broker data were omitted from
    O’Loughlin’s report. Regarding the hearsay objection, the court held that the voice broker data
    were business records. Moreover, because O’Loughlin was an expert, Exhibit 686 could “come
    into evidence based on [O’Loughlin’s] expertise and his representation that he has gone
    through the records.” The court also stated that it relied on the government’s representation
    that the voice broker data had previously been furnished to defendants.
    53
    No. 08-20546; 08-20573
    NGI’s August 2000 Southern California Border Average index. O’Loughlin did
    state that the false trades reported by Singleton had no effect on the volume-
    weighted average.13 During cross-examination, O’Loughlin again acknowledged
    that the volume-weighted average remained the same whether Singleton’s false
    trades were included or excluded. Singleton asserts that the inability of the
    report to change the volume-weighted average undermines O’Loughlin’s
    opinions. This argument does not help Singleton for two reasons. First, it is the
    tendency of a communication to affect a decision maker which is relevant, not
    whether the communication actually had an effect. O’Loughlin posited such a
    tendency after demonstrating the propensity of reported trades to affect volume-
    weighted averages, and the propensity of volume-weighted averages to affect
    indices. Second, if the expert has used reliable methods to assess the data,
    isolated computational or arithmetic discrepancies affect the weight of the
    testimony, not its admissibility. See 
    Daubert, 509 U.S. at 595
    (noting that trial
    courts must focus on experts’ “principles and methodology, not on the
    conclusions that they generate”). O’Loughlin freely noted that Singleton’s report
    of July 31, 2000 would not have changed the volume-weighted average.
    Nevertheless, the jury was free to continue to rely on O’Loughlin’s opinion that
    the false reports had the tendency or capability to affect the indices.
    In sum, the district court properly exercised its duties under Rule 702 and
    Daubert, and did not abuse its discretion in admitting the testimony of Matthew
    O’Loughlin. Defendants are not entitled to a new trial.
    V.
    13
    In contrast, O’Loughlin stated that the false trades reported by Valencia changed the
    volume-weighted average from $4.45 to $4.48.
    54
    No. 08-20546; 08-20573
    Valencia says the numerous evidentiary errors in this case deprived her
    of a fair trial and, cumulatively, mandate a new trial. The government has not
    responded to this argument.
    We have previously recognized the so-called cumulative error
    doctrine under which “an aggregation of non-reversible errors (i.e.,
    plain errors failing to necessitate reversal and harmless errors) can
    yield a denial of the constitutional right to a fair trial.” United
    States v. Munoz, 
    150 F.3d 401
    , 418 (5th Cir. 1999); see United States
    v. Sepulveda, 
    15 F.3d 1161
    , 1195-96 (1st Cir. 1993) (explaining the
    cumulative error doctrine).
    United States v. Williams, 
    264 F.3d 561
    , 572 (5th Cir. 2001). A claim of
    cumulative error is “sui generis;” we evaluate the number and gravity of the
    errors in the context of the case as a whole. See 
    Sepulveda, 15 F.3d at 1196
    .
    To recapitulate our holdings, we have concluded that the government
    committed non-reversible error in reading the letter of Jeffrey Hornback during
    opening statements, and non-reversible error in failing to timely and fully notify
    defense of its fee agreement with Glenn Labhart. We have rejected defendants’
    arguments concerning the propriety of the district court’s evidentiary and
    admissibility rulings, as well as other matters concerning the fairness of their
    trial. We do not condone the government’s missteps. But, we recognize that no
    trial is perfect, and the shortcomings here did not deprive defendants of a fair
    trial. Moreover, the district court assiduously and scrupulously weighed all
    objections which were timely brought to its attention. In the context of the vast
    amount of evidence presented over the course of four weeks, and in light of the
    weight of the evidence supporting defendants’ wire fraud convictions, we reject
    Valencia’s assertion that cumulative error mandates retrial in this case. See 
    id. VI. Both
    Valencia and Singleton argue that the evidence presented was not
    sufficient to sustain their wire fraud convictions. Valencia says the evidence was
    insufficient to show that she submitted false trades, to show her mens rea, and
    55
    No. 08-20546; 08-20573
    to prove materiality. She says Labhart’s testimony did not establish falsity
    because he did not show that the “false” trades listed in the trade reports did not
    actually occur. Valencia posits that not all trades may have been recorded, that
    trade data may have been lost, that there may have been transcription errors,
    and that Labhart’s search may have been unreliable or incomplete. Regarding
    mens rea, Valencia says the jury would have to infer intent from scant evidence
    that her reports did not perfectly match actual bidweek trades. Thus, “the jury
    could only speculate impermissibly whether the mere presence of some
    incongruity was the result of intentionally fraudulent misreporting” or an honest
    error. Finally, Valencia insists materiality was not demonstrated because the
    editors of Inside FERC and NGI said they used editorial discretion to set index
    prices. Singleton similarly argues that there is insufficient evidence of the
    materiality of the false statement he sent on July 31, 2000. Alternatively,
    Singleton says the evidence preponderated against his guilt, such that the
    district court should have ordered a new trial.
    Additionally, defendants have submitted pursuant to Federal Rule of
    Appellate Procedure 28(j) asserting that the government needed to prove that
    the false information provided to Inside FERC and NGI “affected and tended to
    affect index prices.” This language was alleged in the CEA counts of both
    indictments, and was “adopted, realleged and incorporated” into the wire fraud
    counts as well. Defendants insinuate that unless the government has shown
    beyond a reasonable doubt that the false reports affected index prices, the
    materiality element of wire fraud has not been met. Alternatively, defendants
    suggest that failure to prove at trial that their communications “affected and
    tended to affect index prices” constitutes a material variance.
    The government emphasizes that evidence in emails, spreadsheets, and
    other documents, as well as in taped phone conversations, shows that Valencia
    and Singleton engaged in the scheme with the intent to defraud, and that their
    56
    No. 08-20546; 08-20573
    statements were both false and material. The government says that even if the
    witnesses’ statements do not always align, the jury was entitled to credit the
    theory supporting guilt. The government also argues that the allegation that
    defendants’ actions “affected and tended to affect index prices” was mere
    surplusage and not a material variance from the proof at trial.
    A.
    We review de novo the denials of defendants’ motions for judgment of
    acquittal under Federal Rule of Criminal Procedure 29(a). See United States v.
    Myers, 
    104 F.3d 76
    , 78 (5th Cir. 1997). We must affirm the verdict if “a
    reasonable trier of fact could conclude from the evidence that the elements of the
    offense were established beyond a reasonable doubt, viewing the evidence in the
    light most favorable to the verdict and drawing all reasonable inferences from
    the evidence to support the verdict.” 
    Id. The evidence
    “need not exclude every
    reasonable hypothesis of innocence or be wholly inconsistent with every
    conclusion except that of guilt.” 
    Id. at 79
    (quotations omitted). The denial of a
    motion for a new trial under Rule 33(a) is reviewed for an abuse of discretion.
    See United States v. Sipe, 
    388 F.3d 471
    , 492-93 (5th Cir. 2004). To prove wire
    fraud, the government had to show a scheme to defraud, the use of wire
    communications in furtherance of the scheme, defendants’ specific intent to
    participate in the scheme, and materiality of defendants’ communications. See
    18 U.S.C. § 1343; 
    Neder, 527 U.S. at 25
    ; 
    Stalnaker, 571 F.3d at 436
    ; 
    Lucas, 516 F.3d at 339
    .
    B.
    The evidence presented at trial was sufficient to sustain all seven counts
    of wire fraud upon which Valencia was convicted, as well as the sole count of
    wire fraud on which Singleton was convicted.         Jeffrey Hornback testified
    extensively about a scheme at Dynegy to misstate natural gas trades in order to
    benefit Dynegy’s trading position. Hornback’s testimony implicated Valencia in
    57
    No. 08-20546; 08-20573
    the scheme. Valencia’s own recorded phone calls, while at times cryptic or
    oblique, presented evidence from which the jury could infer that Valencia
    knowingly and willingly participated in the scheme. Moreover, for each count
    on which Valencia was convicted, the government showed a communication
    transmitted via the wires by Valencia or at her direction to Inside FERC or NGI.
    The testimony of Glenn Labhart indicated that false information was contained
    in the bidweek reports. While Valencia surmises that Labhart’s testimony might
    not have been wholly accurate, the jury was entitled to reject this hypothesis.
    The properly admitted testimony of Matthew O’Loughlin established that the
    communications were material, i.e., the communications were important to, and
    had the tendency to affect, the decision-makers to whom they were directed. See
    Philip 
    Morris, 566 F.3d at 1124
    ; 
    Lucas, 516 F.3d at 339
    . The jury was entitled
    to believe that the false trades had the tendency to sway the indices,
    notwithstanding the testimony of Doolan and Curran that editorial discretion
    played a role in how the index prices were generated.
    In Singleton’s case, the evidence is likewise sufficient to sustain the guilty
    verdict based on Singleton’s July 31, 2000 report to NGI. The jury could infer
    Singleton’s participation in the scheme to misreport gas trades based upon a
    July 28, 2000 phone call with Valencia. Namely, Singleton and Valencia
    tentatively agree to a sale of gas, but Singleton tells Valencia: “If, if you buy it
    from me you don’t have to report it. I won’t report it.” Valencia replies: “Ok,
    that’s a cool thing.” Alison Reitze, a trader with El Paso, testified that El Paso’s
    records showed a fixed-price baseload trade between El Paso and Dynegy,
    entered into by Singleton and Valencia, respectively, on July 28, 2000. The
    trade met NGI’s reporting criteria, but was not included on the report Singleton
    sent to NGI on July 31, 2001.       Ronald Clay Sanders, the director of risk
    management and analysis for El Paso’s marketing and trading company,
    likewise testified that many of the trades listed in Singleton’s July 31, 2000
    58
    No. 08-20546; 08-20573
    report to NGI were not listed in El Paso’s risk management database. The
    foregoing facts adequately show Singleton’s knowing participation in, and use
    of the wires in furtherance of, a scheme to misreport trades.
    Singleton again suggests that the false trades were not material because
    NGI’s Southern California Border index was the same whether his trades were
    included or excluded.    He also states that O’Loughlin misrepresented the
    testimony of Mark Curran, chief editor of NGI, regarding how the index was
    calculated. Singleton emphasizes that Curran testified that he had no record of
    how he created the index, and that the index price was entirely at his discretion.
    As discussed above, even if the false trades reported by Singleton did not change
    the index, this does not mean the communication was immaterial. See Philip
    
    Morris, 566 F.3d at 1124
    ; 
    Lucas, 516 F.3d at 339
    . Success is not an element of
    the crime. See 
    Loney, 959 F.2d at 1337
    . O’Loughlin’s testimony also presented
    evidence which, if found credible by the jury, would support a well-grounded
    inference that trade reports from Singleton and other natural gas traders were
    important to Curran, regardless of his undisputed editorial discretion. At most,
    Singleton’s arguments concern the weight the trier of fact could assign to various
    pieces of evidence. Because a reasonable jury could have found each element
    present beyond a reasonable doubt, Singleton’s wire fraud conviction stands.
    C.
    The language in defendants’ indictments is not defective or a material
    variance from the proof adduced at trial. We normally disregard arguments not
    briefed or raised for the first time at or after oral argument. See, e.g., United
    States v. Whitfield, 
    590 F.3d 325
    , 370 (5th Cir. 2009). At best, we may review for
    plain error. 
    Id. at 371.
    Even so, defendants’ arguments lack merit. We have
    long held that the government need only prove facts alleged in the indictment
    which meet the essential elements of the crime. United States v. Robinson, 
    974 F.2d 575
    , 578 (5th Cir. 1992); United States v. England, 
    480 F.2d 1266
    , 1269 (5th
    59
    No. 08-20546; 08-20573
    Cir. 1973). We treat the allegation of additional facts beyond those which
    comprise the elements of the crime as “mere surplusage.” 
    Robinson, 974 F.2d at 578
    . The materiality element of wire fraud does not require a showing that
    a false communication actually caused an intended consequence. Thus, the
    allegation in the indictment that Valencia and Singleton “affected and tended
    to affect index prices” is surplusage. See id.; United States v. Hughes, 
    766 F.2d 875
    , 879 (5th Cir. 1985).
    There was also no material variance between the indictment and the proof
    at trial. “A variance is material if it prejudices the defendant’s substantial
    rights, either by surprising the defendant at trial or by placing the defendant at
    risk of double jeopardy.” 
    Robinson, 974 F.2d at 578
    (citations and internal
    quotations omitted). A variance is immaterial if the nature of the charge
    remains the same. See id.; see also United States v. Millet, 
    123 F.3d 268
    , 272
    (5th Cir. 1997) (“A constructive amendment to the indictment occurs when the
    jury is permitted to convict the defendant on a factual basis that effectively
    modifies an essential element of the offense charged in the indictment.”)
    (citations omitted). In this case, the wire fraud scheme alleged in the indictment
    was the same as that demonstrated at trial, namely, that defendants submitted
    false natural gas trade reports to Inside FERC and NGI. The success of the
    schemes is not relevant to wire fraud. Therefore, defendants could not have
    been surprised or exposed to double jeopardy for these counts if the proof did not
    demonstrate an unequivocal causal effect between the reports and changes to
    the indices. See 
    Robinson, 974 F.2d at 578
    . There was no plain error. See
    
    Millet, 123 F.3d at 272
    .
    In sum, there was sufficient evidence to sustain all counts on which the
    jury returned verdicts of guilty. We reiterate that we have only reviewed the
    sufficiency of the counts of wire fraud. We have not considered the conspiracy
    counts, nor the substantive counts of violations of the Commodities Exchange
    60
    No. 08-20546; 08-20573
    Act, which were dismissed at the government’s motion in light of the jury’s
    partial verdict. We express no opinion regarding whether the evidence was
    sufficient to support such counts.
    VII.
    Finally, Valencia argues that the district court erred in failing to consider
    whether she was entitled to a downward departure based on her caregiver
    status. Sentencing took place on August 21, 2008, more than two years after
    trial. The Guidelines range was forty-six to fifty-seven months. Valencia had
    recently given birth to a daughter with Turner’s syndrome, and requested a
    departure for this reason. The court said Valencia’s decision to conceive and
    carry a child to term, despite her imminent incarceration, “was a personal
    choice. . . . I cannot change my sentence for that reason.” The court sentenced
    Valencia to concurrent fifty-seven month terms of imprisonment, the top of the
    Guidelines range, followed by concurrent two-year terms of supervised release.
    Valencia avers that the court’s statement, “I cannot change my sentence for that
    reason,” reveals the district court’s failure to comprehend its broad authority to
    grant a departure.     See Gall v. United States, 
    552 U.S. 38
    , 49-50 (2007).
    Valencia requests resentencing. The government counters that the court’s
    statement reflects its understanding of its duties to uphold the law and apply the
    faactors of 18 U.S.C. § 3553(a), and not a sense that it lacked discretion to grant
    a downward departure.
    Review of a district court’s sentence is governed by a two-step process, in
    which we first ask whether the district court committed a procedural error.
    United States v. Delgado-Martinez, 564 F.3d 750,751 (5th Cir. 2009). If there is
    no error or the error is harmless, we review the substantive reasonableness of
    the sentence for an abuse of discretion. Id.; see 
    Gall, 552 U.S. at 51
    . There is no
    indication, nor does Valencia argue, that the court committed a procedural error
    in calculating the Guidelines range. Moreover, the court acknowledged its
    61
    No. 08-20546; 08-20573
    authority and responsibilities, including those stated in Kimbrough v. United
    States, 
    552 U.S. 85
    (2007), United States v. Booker, 
    543 U.S. 220
    (2005), and
    under § 3553(a). The court’s statement does not indicate misapprehension of its
    authority to give Valencia the sentence it deemed proper, whether within, above,
    or below the Guidelines range. The court also stated to Valencia: “I’m going to
    give you the sentence that I think is the right sentence regardless of the
    Guidelines.” The court thereafter explicitly acknowledged that the Guidelines
    were not binding, and that the court had the authority to deviate if it so chose.
    In context, the words “I cannot” are best understood as “I will not.” This isolated
    comment does not indicate that the district court believed that the Guidelines
    range should presumptively apply. See United States v. Cisneros-Gutierrez, 
    517 F.3d 751
    , 766 (5th Cir. 2008). Valencia is not entitled to resentencing.
    VIII.
    We have exhaustively examined the vast trial record, defendants’
    arguments on appeal, and the relevant law. We conclude that defendants’
    convictions withstand each of the challenges raised. We therefore affirm the
    convictions and sentences of defendants Valencia and Singleton.
    AFFIRMED.
    62