Securities Law Commons^™

Mismatch: The Misuse Of Market Efficiency In Market Manipulation Class Actions, Charles R. Korsmo

Faculty Publications

Plaintiffs commonly bring two distinct types of claims under Section 1(b) of the Securities Exchange Act of 1934: 1) claims of material misrepresentations or omissions; and 2) claims of trade-based market manipulation. Despite the distinctive features of the two types of claims, courts have tended to treat them identically when applying the “fraud on the market” doctrine. In particular, courts have required both types of plaintiffs to make identical showings that the relevant security traded in an “efficient market” in order to gain a presumption of reliance. The reasons for requiring such a showing by plaintiffs in a misrepresentation case …