Aug. 5, 2011, 12:39 p.m. EDT Thursday's slide triggers 460 short-sale limits WASHINGTON (MarketWatch) - Across U.S. markets roughly 460 stocks triggered the Securities and Exchange Commission's short sale rule during Thursday's market downturn, according to data tracked by the New York Stock Exchange. The SEC's short sale rule restricts the prices at which a stock can be sold short if the stock's price drops 10% or more in one day. When the rule is invoked, traders are only allowed to sell the stock short at a price above the highest national bid to relieve rapid selling pressure. On Thursday, the Dow Jones Industrial Average suffered its worst single-point drop since December 2008.