Information on Computer Data Used for Stock Market Crash Studies
IMTEC-88-57: Published: Sep 15, 1988. Publicly Released: Sep 20, 1988.
- Full Report:
Pursuant to a congressional request, GAO reviewed allegations that the New York Stock Exchange (NYSE) supplied certain trading and order execution data to a consultant, but not to the Securities and Exchange Commission (SEC) and the Presidential Task Force on Market Mechanisms for use in their studies of the October 1987 stock market crash.
GAO found that: (1) the data detailed minute-by-minute information on program and nonprogram trades made on October 19, 1987, including the dollar value and number of orders and number of shares per order; (2) the SEC and task force studies examined the effect of program trading by surveying 16 large program-trading firms which were active in the futures markets; and (3) SEC provided all of the information it collected to the presidential task force. GAO also found that both SEC and the presidential task force: (1) verified their survey data against NYSE audit trail and daily transaction data detailing the number of executed stock trades; (2) were aware of the availability of the data NYSE provided to its consultant, but believed that the data were incomplete; (3) used NYSE program trading data to confirm the accuracy of their survey information; (4) based their studies on an analysis of the number of times NYSE entered each executed stock trade into its order processing system; and (5) believed that the short time frame and data limitations prevented them from conducting a more rigorous quantitative analysis of trading data.