What is a Stock

A stock is a piece of paper that signifies that you own part of
a company. The market price of a stock is directly related to
the profits and the losses of the company. In other words,
when the company profits, the worth of your stock increases.
When the company falters and its profits decline, so does the
worth of your stock.
Investors who buy stock own shares of the company. That’s
why they’re called shareholders.