The stock market is a collection of markets where stocks (pieces of ownership in businesses) are traded between investors. It usually refers to the exchanges where stocks and other securities are bought and sold. The stock market can be used to measure the performance of a whole economy, or particular sectors of it. It is often considered a leading indicator, as stock prices tend to change before the rest of the economy. For example, if company ABC is doing well, its stock price will rise, and this might be a sign that the whole economy is doing well.

There are different types of stock markets, including exchanges and over-the-counter markets. The two most well-known exchanges are the New York Stock Exchange (NYSE) and the Nasdaq. The NYSE is located on Wall Street in New York City, and it is the largest stock exchange in the world by market capitalization. The Nasdaq is also located in New York City, but it is a electronic exchange. It is the second largest stock exchange in the world by market capitalization. Other well-known exchanges include the London Stock Exchange (LSE) and the Tokyo Stock Exchange (TSE).

Most stock markets are open from 9:30 a.m. to 4:00 p.m. EST, Monday through Friday. However, there are some exceptions. For example, the Hong Kong Stock Exchange (HKEX) is open from 9:30 a.m. to 4:00 p.m. HKT (Hong Kong Time) on weekdays, which is 8:30 p.m. to 3:00 a.m. EST. The NYSE and Nasdaq are both open from 9:30 a.m. to 4:00 p.m. EST on weekdays. However, they are also open for extended hours. After-hours trading on the NYSE and Nasdaq begins at 4:00 p.m. EST and ends at 8:00 p.m. EST. Pre-market trading begins at 8:00 a.m. EST and ends at 9:30 a.m. EST. The stock market is closed on weekends and holidays. For example, it is closed on New Year's Day, Martin Luther King Jr. Day, and Christmas Day. 

Source: stockregion.com

The New York Stock Exchange (NYSE)

The New York Stock Exchange (NYSE) is the world's largest stock exchange by market capitalization. The main index for the NYSE is the Dow Jones Industrial Average (DJIA). The stock market opens at 9:30 a.m. EST on weekdays, but it is closed on weekends and holidays.

The Nasdaq

The Nasdaq Stock Market is a stock exchange located in New York City. It is the second-largest stock exchange in the world by market capitalization, behind only the New York Stock Exchange. The Nasdaq is owned by Nasdaq, Inc., which also owns the Nasdaq Nordic stock market network and several other US stock and options exchanges. The Nasdaq Stock Market began trading on February 8, 1971. It was the world's first electronic stock market. The Nasdaq is open Monday through Friday from 9:30 a.m. to 4:00 p.m. Eastern Time.

Other US exchanges

The New York Stock Exchange (NYSE) is the world's largest stock exchange by market capitalization. Located in New York City, the NYSE is home to more than 2,800 listed companies with a market capitalization of over $16 trillion as of June 2019. The stock market opens at 9:30 a.m. EST on weekdays (except for holidays), and closes at 4:00 p.m. EST.

The Nasdaq Stock Market is the second-largest stock exchange in the world by market capitalization, behind the NYSE. The Nasdaq is home to more than 3,000 listed companies with a market capitalization of over $11 trillion as of June 2019. The Nasdaq Stock Market is open from 9:30 a.m. to 4:00 p.m. EST on weekdays (except for holidays).

Source: stockregion.com