An unexpected one-off financial gain in cash or shares, generally when mutual building societies convert to stock market-quoted banks. Also windfall tax, a one-off tax imposed by government. The UK government applied such a measure in the Budget of July 1997 on the profits of privatised utilities companies.
The term is interchangeable with stock exchange, and is a market that deals in securities where market forces determine the price of securities traded. Stockmarket can refer to a specific exchange in a specific country (such as the London Stock Exchange) or the combined global stockmarkets as a single entity. The first stockmarket was established in Amsterdam in 1602 and the first British stock exchange was founded in 1698.