Did Some Investors Know about 9-11 in Advance? A person who knew about 9-11 in advance could have profited by buying Put options on the market. A put is the right to sell a stock to another person at a fixed price. After making a large investment in Put options, the person would wait for the predictable decline in stock prices following the attacks. The Put options would then skyrocket in value. Finance professor Allen Poteshman has examined behavior in the options market leading up to the 9-11 terrorists attacks.

When the option market activity in the days leading up to the terrorist attacks is compared to the benchmark distributions, volume ratio statistics are seen to be at typical levels. An indicator of long put volume, however, appears to be unusually high which is consistent with informed investors having traded in the option market in advance of the attacks.