Justice White, joined by Justice O'Connor, dissented from the Court's acceptance of the fraud-on-the-market presumption. Although he agreed that any such presumption must be rebuttable and cannot permit recovery by investors who did not rely on price at all, he believed the Court was improperly reshaping the reliance requirement through an uncertain economic theory.
In his view, courts lack the institutional competence to make securities-law rules depend on the efficient-capital-market hypothesis and disputed assumptions about how market professionals incorporate information into stock prices. Congress, with greater expertise and fact-finding capacity, should decide whether modern market theory warrants altering traditional reliance principles.
Justice White also argued that the presumption effectively weakens reliance to the point of near elimination. Investors often trade because they believe the market price is wrong, not because they believe it accurately reflects a security's true value. He feared that rebuttal would be difficult in practice and that the doctrine would move Rule 10b-5 toward investor insurance rather than liability for actual fraud.
He read Congress's treatment of the Securities Exchange Act's express civil-liability provisions as favoring meaningful reliance. Congress revised an early proposal that would have allowed recovery merely because a misleading statement affected a security's price, adding an express reliance requirement instead. For Justice White, that legislative history counseled against a judicially created price-based presumption under Rule 10b-5.
Finally, Justice White thought Basic's facts exposed the doctrine's practical defects. The plaintiffs were sellers over a lengthy fourteen-month period, many sold at a profit, and the stock price rose despite Basic's denials. He worried that sophisticated investors who disbelieved the denials and speculated successfully on a possible merger could nevertheless recover, with the costs ultimately borne by innocent shareholders.