The SEC announced yesterday that following an extensive investigation it began the day after the Sept. 11 terrorist attacks on the U.S., it had found no evidence suggesting that anyone who had advance knowledge of the September 11 attacks traded on the basis of that information. The SEC stated that in the course of its investigation, it examined more than 9.5 million securities transactions that took place during the weeks preceding September 11; reviewed trading in securities and derivative products of 103 companies in six industry groups with trading in seven markets; and reviewed trading in 32 exchange traded funds and broad and narrow indices.

As discussed in this Chicago Tribune article, reports emerged shortly after the terrorist attacks that in the days leading up to Sept. 11, "some traders placed unusually large bets for stock prices to fall at several firms, particularly for the parent companies of United and American Airlines, whose planes were hijacked and used in the attacks. That prompted speculation that some people who knew about the attacks also had sought to make a quick buck." The article notes that immediately following Sept. 11, shares of UAL dropped 43 percent and shares of AMR fell 39 percent, and that potential profits from the UAL options trading alone were more than $4 million.

According to the SEC's investigation, which was incorporated in the just-released report of the bipartisan 9/11 Commission, each trade had "an innocuous explanation." The commission report stated that a U.S. institutional investor "with no conceivable ties to Al Qaeda" bought 95 percent of UAL put options on Sept. 6 as part of a trading strategy that also saw it buy shares of AMR, and a sharp climb in AMR put options volume on Sept. 10 resulted from a recommendation in an options-trading newsletter.