The rapid selling of a security by a large number of investors. This increases the supply of the security available for sale while leaving constant or decreasing the demand to buy; this drives down the price. Selling panics occur for a number of reasons. For example, a stock may drop suddenly in price if its company issues an unexpectedly negative earnings report. The panic comes from investors' desire to sell the stock immediately before the price falls even more. See also: Buying panic, Sell-off.
A period of rapidly falling stock prices on very large volume as investors, speculators, traders, and institutions attempt to liquidate investment positions without regard to price. Selling panics occur when individuals and institutions believe they must sell securities at once before prices fall further. Compare buying panic.