Exchange

Exchange is a place or organization where shares, currencies, commodities, etc. are bought and sold [Cambridge Online Dictionary].
An exchange is a marketplace where securities, commodities, derivatives, and other financial instruments are traded. The core function of an exchange is to ensure fair and orderly trading and the efficient dissemination of price information for any securities trading on that exchange. Exchanges give companies, governments, and other groups a platform to sell securities to the investing public [Investopedia].

Sources:

Exchange. Cambridge Online Dictionary. Retrieved from: https://dictionary.cambridge.org/dictionary/english/exchange

Exchanges: Explanation, Types and Examples. Investopedia. Retrieved from: https://www.investopedia.com/terms/e/exchange.asp