The use of British common law to inhibit insider trading has been discussed frequently in recent years. Section 13 of the Prevention of Fraud Act generally provides that any person who attempts to promote security sales through misrepresenting or concealing facts is guilty of a criminal offense and subject to a maximum prison term of 7 years. Although these provisions were enacted to combat frauds committed by securities dealers in publicly traded stocks, their scope could be broadened. The few cases prosecuted under Section 13 have turned essentially on the question of recklessness in making a false statement and whether it is necessary to show dishonesty. Although many lawyers do not consider insider trading dishonest, members of the public and the courts have condemned such conduct. Knowingly making a false statement, dishonest concealment of a material fact, and recklessly making a false statement should be considered separate offenses and not combined as in civil law on deceit and misrepresentation. Regarding the ambiguous concept of concealment, Section 13 imposes a duty to make full disclosures of information relevant to a particular securities transaction, and failure to do so could be considered dishonest. It has been assumed that the defendant will be a corporate director or officer, but the same measures could be applied to a substantial stockholder. Much would depend on the circumstances of individual cases, but there is no valid reason why the judicial system should not create a category of persons whose intentional concealment of information that they have obtained through a confidential relationship with a company would be judged dishonest. If Section 13 is accepted as a legal means of inhibiting insider trading, questions arise over whether it is applicable to all securities transactions or just those executed on a face-to-face basis. By asserting that an insider who is trading on an anonymous stock exchange induces other persons to enter into transaction with him, it might be possible to expand the law's scope. Proof of possession of confidential information and the intention to use it to the detriment of another would provide a basis for showing the materiality required by Section 13. Since the 1958 law does not provide for fines or victim compensation, specific civil liabilities should be established. The article contains 47 footnotes. (Author abstract modified)