The trading activities that take place after official trading hours- often contrary to exchange rules. In other words, this implies the trading of securities that occurs not at regulated markets, but rather through computers and telephone lines after the official trading session of an exchange. The name “kerb” or “curb” came from the practice of exchange members, in the early 1900s, meeting on the roadside by the kerb to continue trading after normal trading hours. On other occasions, stocks that were not qualified to trade on a major exchange were bought and sold in the street on the curb outside the market. In the U.S, kerb trading is an illegal practice (under the rules of CFTC and the Commodity Exchange Act).

It is also known as curb trading.