Exchange

An association, organization, or group of persons, incorporated or unincorporated, that constitutes, maintains, or provides a marketplace or facilities for bringing together purchasers and sellers of SECURITIES or commodities futures.

A security is a written proof of ownership of an investment, usually in the form of shares of stock, which are fractional units of ownership in a company. Commodities are raw materials, like wheat, gasoline, or silver, that are sold either on the spot market, where cash is paid "on the spot," or through futures contracts, where a price for a contract is set in advance, not to be changed even if the market price for the commodity increases or decreases by the time the contract comes due.