Short Selling

Short selling is a strategy used by investors to make profits from the falling price of a security. It involves "borrowing" a security from a broker, selling it and then buying it back at a lower price in order to return it to the broker. Short selling is often used by investors who believe that the price of an asset is overvalued and will decline in the future. 

For example, an investor may borrow shares of a company at $10 each and sell them. If the price of the stock drops to $8, the investor can buy back the shares to repay the loan, making a profit of $2 per share. 

One famous example of short selling is when during the lead-up to the 2008 financial crisis, Michael Burry, a hedge fund manager, bet against the subprime mortgage market by shorting mortgage-backed securities. His bet paid off when the housing market collapsed, earning him and his investors significant profits.

It's important to note that short selling is a risky investment strategy, and investors can lose money if the price of the asset they've shorted rises instead of falling.