The Securities and Exchange Commission began its inquiry into the matter on Sept. 12, 2001, and went on to examine trading in the U.S. and foreign securities markets that took place between Aug. 20 of that year and Sept. 11. While the agency wrapped up its investigation in May 2002, and there were references to the SEC's conclusions in the report by the federal 9/11 Commission, the findings were kept secret.
But the privately operated, nonpartisan National Security Archives fought for six years to make the SEC report public, an effort aided by the Obama administration's push to declassify documents across the spectrum of government affairs. And today, most of the SEC's "Pre-September 11, 2001 Trading Review" was made public.
"We have not developed any evidence that suggests that those who had advance knowledge of the attacks traded on the basis of that information," the SEC said. "In every instance where we noticed unusual trading before the attack, we were able to determine, either through speaking directly with those responsible for the trading, or by reviewing trading records, that the trading was consistent with a legitimate trading strategy."
The SEC said it looked at 9.5 million securities transactions involving 103 companies in six industry groups and trading in seven financial markets.
The inquiry's early focus was on the shares of UAL Corp. and AMR Corp., parent companies of United Airlines and American Airlines, whose planes were guided by terrorists into the World Trade Center towers and the Pentagon, as well as one brought down in a Pennsylvania field after passengers attacked the hijackers aboard.
But the probe quickly widened to financial firms with significant operations in the World Trade Center and insurance companies that faced billions of dollars in losses following the attacks. Securities tied to defense and aerospace companies, security firms and travel and leisure services were examined as well.
Shares in AMR and UAL dropped 40 percent or more after financial markets reopened on Sept. 17, 2001. And the commission's investigators found that short selling -- a means of betting against the companies -- substantially increased for UAL on Sept. 6 and for AMR on Sept. 10 of that year.
Yet interviews with the financial advisers and traders who initiated those transactions found they based their decisions on several bearish factors already affecting the airline industry, including widely distributed recommendations for short selling from a California newsletter called Options Hotline.