Opinion by
Mr. Justice Elkin,
This is an action of trespass for damages claimed to have been suffered by reason of an alleged conspiracy fraudulently and maliciously entered into by defendants to cheat and defraud the public in general and the appellant in particular. In order to sustain a recovery the burden is on appellant to prove by sufficient testimony that such a conspiracy was entered into in the first place, and that as a result of the fraudulent acts done and false statements made for the purpose of furthering the scheme to defraud, he was induced to invest in the preferred stock purchased by him at a price in excess of its real value. Conspiracy is a combination or agreement between two or more persons to do an unlawful thing, or to do a lawful thing in an unlawful manner. A conspiracy to defraud on the part of two or more persons means a common purpose supported by a concerted action to defraud, that each has the intent to do it, and that it is common to each of them, and that each understands that the other has that purpose: United States v. Frisbie, 28 Fed. Repr. 808. In the case at bar seven defendants are charged with conspiracy, but it is conceded there is no evidence against four of them, and certainly as to the other three the evidence is not sufficient to show concerted action or common intent or collusive understanding or unlawful combination to cheat and defraud appellant.
A conspiracy may be proven either by direct and positive testimony showing that a collusive agreement had been entered into to do an unlawful thing, or by acts and circumstances sufficient to warrant an inference that the unlawful *631combination had been in point of fact formed for the fraudulent purpose charged, and when circumstantial evidence is relied on to prove the conspiracy its sufficiency must first be determined by the court. It must not be overlooked that in a suit alleging conspiracy between two or more persons, the foundation of the action is the unlawful combination. Failure to prove the unlawful combination defeats the right to recover, and the unlawful combination, like any other substantive fact, must be established by sufficient relevant testimony. If the testimony is direct and positive as a rule the question of sufficiency cannot arise, and in such cases it is for the jury to pass upon the credibility of witnesses and determine the fact by the weight of the evidence. When the testimony is not direct and positive, but where subsequent acts and circumstances are relied on to establish the conspiracy, a very different situation is presented. In such a case the first duty rests with the court to say whether the proven acts and circumstances, even if believed, are sufficient in law to establish in point of fact that the unlawful combination had been entered into by the parties charged, or two or more of them at some prior date. If the subsequent acts do not show, or tend to show, the prior unlawful combination and purpose, the very foundation of the action, it is clear the plaintiff has failed to make out his case and it is the duty of the court to say so. It may be, and no doubt is, often difficult to determine when the subsequent acts relied on are sufficient to establish the conspiracy and when they should be deemed insufficient. These, however, are difficulties with which courts are frequently confronted and which must be met and determined with an eye single to the legal rights of the parties. When conspiracy is alleged it must be proven by full, clear and satisfactory evidence. This measure of proof is recognized in all our cases as the correct rule, and while it is permissible to prove subsequent acts from which the conspiracy itself may be inferred, when such acts are relied on to establish the conspiracy they must be such as to clearly indicate the prior collusive combination and fraudulent purpose, not slight circumstances of suspicion upon which a jury might guess or conjecture as to the fact of such unlawful combination ever having been entered into, but they must be such as to warrant the belief and jus*632tify the conclusion that the subsequent acts were done in furtherance of the unlawful combination and in pursuance of the scheme to defraud. The subsequent acts must negative the idea of a lawful undertaking or purpose, and must tend to show the prior unlawful combination. If the subsequent acts show an honest purpose or a lawful transaction, it would do violence to the settled rules of evidence and to the legal rights of parties to hold that testimony which shows subsequent lawful acts is sufficient to establish a prior unlawful combination. The burden is on him who alleges a conspiracy as the foundation of his suit to prove it by sufficient testimony, and, failing to do so, his action falls. A. conspiracy must be proven by substantive facts, not by disconnected circumstances, any one of which, or all of which are more consistent, or just as consistent, with a lawful purpose as with an unlawful undertaking.
In the present case there is no direct or positive testimony showing or tending to show that an unlawful combination had ever been formed by the defendants, or by two or more of them, to cheat and defraud appellant, and the subsequent acts of some of the defendants proven at the trial, and the rejected offers of testimony relating to the sales of common stock on the stock exchange, in no way connected with the purchase of preferred stock at private sale, or with any dealings between appellant and appellees concerning the purchase and sale of the particular stock upon which this suit is based, fall far short of being sufficient to establish an unlawful combination. Under such circumstances it was the duty of the court to take the responsibility by directing the jury to return a verdict for defendants, which the learned trial judge did, and in so doing he followed the rule of our own cases: Newall v. Jenkins, 26 Pa. 159 ; Gaunce v. Backhouse, 37 Pa. 350 ; Benford v. Sanner, 10 Pa. 9 ; Mead v. Conroe, 113 Pa. 220 ; Collins v. Cronin, 117 Pa. 35 ; Nat. Bank v. Tinker, 158 Pa. 17.
The first eight assignments of error relate to the refusal of the court to allow appellant to show the listing of the common stock of the Daylight Prism Company on the Philadelphia Stock Exchange and the sales of said stock by the defendants and others through brokers. The transaction about which appellant complains was the purchase by him of preferred *633stock, not listed nor sold on the stock exchange at the time, and in the rejected offers of testimony, it was not proposed to show that the sales of common stock affected the value of the preferred stock, or that it was part of a conspiracy to cheat and defraud, or that when the preferred stock was purchased the price paid for same did not represent its then market value, or that he relied on the quotation of the common stock when he purchased the preferred shares at private sale. The rejected offers of testimony were too indefinite, vague and remote to sustain the allegation of conspiracy and were properly excluded. Nor is McElroy v. Harnack, 213 Pa. 444, authority for a different rule. It is true in that case the plaintiffs were permitted to show that the brokers by what is known as wash or fictitious sales on the stock exchange gave the bonds a high market value, more than their real worth, which enabled the other defendants to borrow money in excess of their value by using the bonds as collateral. It is clear, however, that the whole transaction in that case from the incorporation of the company, the purchase of incumbered real estate, the execution of a mortgage greatly in excess of the value of the property, the issuance of bonds on the same, and the sale of these bonds fictitiously on the stock exchange, was part of a collusive scheme to defraud the public or individuals who had anything to do with the bonds as a purchaser or as a lender of money with them as collateral. Then, again, the brokers in that case who manipulated the fictitious sales were two of the defendants and they had been connected with the collusive scheme from its inception. None of these facts appear in the present case.
The remaining assignments of error, relating to the declaration of dividends and the exclusion of testimony tending to show control of the company by defendants, are without merit under the facts of this case. The excluded testimony, if admitted and believed, was not sufficient to establish a conspiracy to cheat and defraud appellant in the purchase of his preferred stock, and since this is the foundation upon which the right to recover depends, the suit must fall.
Judgment affirmed.