What is the option to sell shares of stock at a specific time in the future called?

The option to sell shares of stock at a specific time in the future is called a "put option." A put option gives the holder the right, but not the obligation, to sell a specified number of shares at a predetermined price, known as the strike price, before or at the option's expiration date. This financial instrument is often used by investors to hedge against potential declines in stock prices.