A stock, also known as equity, is a security that represents a fractional share of ownership in a company. When you purchase a stock from a company, you become a shareholder, and the small piece you own is called a share.  Investors buy and own stocks in hopes that the company will succeed. When the company does well, its stock owners share in those profits. Conversely, shareholders can also expect their returns to be diminished if the company underperforms or declines. And in the worst-case scenario, a stock owner's shares could become worthless if the company was to go bankrupt. Follow News about the stock market and make investments better!