Put
An options contract that gives the buyer the right, but not the obligation, to sell the underlying asset at the strike price before expiration.
Explanation
Put options increase in value as the underlying asset declines. Buyers pay a premium for downside protection or bearish speculation. Sellers collect premium and accept the obligation to buy if assigned. Puts are used for hedging, bearish strategies, and income generation (cash-secured puts).
Example
Buying a $140 put on AAPL for $2.00 gives you the right to sell 100 shares at $140 until expiration. If AAPL drops to $130, the put is worth at least $10.