Similarly, if you believe the company’s share price is going to dip to $80, you’d buy a put option (giving you the right to sell shares) with a strike price above $80 (ideally a strike price no lower than $80 plus the cost of the option, so that the option remains profitable at $80). If the stock drops below the strike price, your option is in the money.
Options belong to the larger group of securities known as derivatives. A derivative's price is dependent on or derived from the price of something else. As an example, wine is a derivative of grapes ketchup is a derivative of tomatoes, and a stock option is a derivative of a stock. Options are derivatives of financial securities—their value depends on the price of some other asset. Examples of derivatives include calls, puts, futures, forwards, swaps, and mortgage-backed securities, among others.
An option is a contract that allows (but doesn't require) an investor to buy or sell an underlying instrument like a security, ETF or even index at a predetermined price over a certain period of time. Buying and selling options is done on the options market, which trades contracts based on securities. Buying an option that allows you to buy shares at a later time is called a "call option," whereas buying an option that allows you to sell shares at a later time is called a "put option."