Stock Market
The stock market is the network of exchanges and trading venues where shares of publicly listed companies are bought and sold.
The stock market is not one single place. It is a collection of exchanges, such as the NYSE and Nasdaq, along with other electronic trading venues where investors buy and sell shares. Together they let companies raise money from the public and let investors trade those shares with each other.
There are two parts. In the primary market, a company sells new shares directly to investors, for example in an IPO. In the secondary market, investors trade existing shares among themselves. Most everyday trading happens in the secondary market, and the company does not receive money from those trades.
Prices are set by supply and demand. When more people want to buy a stock than sell it, the price rises, and vice versa. News, earnings reports, economic data and interest rates all influence that balance.
When people say the market went up today, they usually mean a major index such as the S&P 500 or the Dow Jones Industrial Average rose. Regular US trading hours run from 9:30 a.m. to 4:00 p.m. Eastern Time on business days.