Business Notes Stocks

Securities and Exchange Commission officials are still trying to figure out what happened on Wall Street on Sept. 11 and 12, when the Dow Jones industrial average plunged a record 121 points. The drop happened a week before the stock exchanges' now notorious "triple-witching hour," the quarterly expiration deadline for stock options, stock-index futures and stock-index options. In the past, massive computer-triggered "program trading" has pushed the market up or down steeply when the witching hour struck. Now the SEC has decided to look into such selling waves whenever they occur. Whether anything can then be done about the phenomenon is unclear. As if to emphasize this point, the Dow slumped almost 35 points in a single day last week, before closing Friday at 1769.69, 7 points higher than a week earlier.