Stock exchange
A stock exchange is a marketplace where shares of publicly listed companies are bought and sold. The New York Stock Exchange and the are the two largest in the United States, and most countries have at least one exchange of their own.
A company lists its shares on an exchange through an or a , and from that point its price is set continuously by trading. In the United States that trading is spread across many exchanges and off exchange venues, not only the exchange where the is listed. Exchanges are regulated venues with listing requirements companies must meet and maintain, which is part of what gives investors confidence that trading on them is fair and transparent.