A put is a contract that gives you the right to sell a stock at a set price by a certain date

When you buy a put option, you are paying for the right — but not the obligation — to sell 100 shares of a specific stock at a price you lock in today, even if the stock price falls below that level later. That locked-in price is called the strike price. The date by which you must use or abandon that right is called the expiration date. You pay an upfront cost, called the premium, to own the put.

Puts work in the opposite direction from calls. If you own a call, you profit when the stock price rises. If you own a put, you profit when the stock price falls. The lower the stock trades below your strike price, the more your put is worth.

Key Takeaways

  • A put gives you the right to sell 100 shares at a fixed price (the strike) before the expiration date, regardless of where the stock actually trades.
  • You pay a premium upfront to buy a put, and that premium is the most you can lose on the trade.
  • Puts make money when the stock price falls below your strike price, because you can sell at the higher strike price or sell the put contract itself for a profit.
  • Most individual investors buy puts to protect against losses in stocks they already own, rather than to bet on a price drop alone.
  • Puts expire on a specific date, and if the stock never falls below your strike price by that date, your put expires worthless and you lose the premium you paid.

How a put makes money when a stock falls

Imagine you buy a put on XYZ stock with a strike price of $50 and you pay $2 per share ($200 total for the contract, since one option contract covers 100 shares). If XYZ falls to $40 before expiration, your put is now worth at least $10 per share ($1,000 total) because you have the right to sell at $50 when the market price is only $40. You can sell that put contract to another investor for a profit, or you can exercise it and actually sell 100 shares of XYZ at $50.

If XYZ stays at $50 or rises, your put loses value. If XYZ is still at $50 when the put expires, the put is worthless — you would not pay $50 to sell something worth $50 in the open market. In that case, you lose the $200 premium you paid upfront.

Why homeowners and long-term investors use puts

Most people who buy puts are not betting that a stock will crash. Instead, they own the stock and want insurance against a sudden drop. This is called a protective put. If you own 100 shares of a stock trading at $60 and you are worried it might fall, you can buy a put with a $55 strike price. Now, if the stock drops to $40, you can still sell your shares at $55. The put acts like an insurance policy.

The trade-off is that you pay the premium whether or not the stock falls. If the stock stays at $60 or rises, you have paid for protection you did not need. But if the stock does fall sharply, the put limits your loss. This is why protective puts are common during uncertain market periods or when you own a stock you believe in long-term but want to guard against short-term risk.

The difference between buying and selling puts

When you buy a put, you pay the premium and you profit if the stock falls. Your loss is limited to the premium you paid. When you sell a put (also called writing a put), you collect the premium upfront but you take on the obligation to buy 100 shares at the strike price if the stock falls below it. Selling puts is a more advanced strategy and carries much higher risk because your potential loss is much larger than the premium you collected.

Most new investors start by learning to buy puts, not sell them. Selling puts requires margin (borrowed money) and exposes you to losses that can exceed the premium you received.

What happens when a put expires

Put options have a fixed expiration date — typically the third Friday of the month for standard options, though some expire weekly or on other schedules. On expiration day, if the stock price is above your strike price, your put expires worthless and you lose the entire premium. If the stock is below your strike price, you can exercise the put and sell 100 shares at the strike price, or you can sell the put contract itself to capture whatever value remains.

You do not have to hold a put until expiration. Most investors sell the put contract before expiration if it has gained value, locking in a profit without ever exercising it or owning the underlying stock.

The cost of a put and what affects it

The premium you pay for a put depends on several factors: how far the strike price is from the current stock price, how much time remains until expiration, how volatile the stock is, and the overall interest rate environment. A put with a strike price close to the current stock price costs more than a put far below it, because it is more likely to be profitable. A put that expires in three months costs more than one expiring in two weeks, because there is more time for the stock to fall.

Stocks that swing wildly in price have more expensive puts than stable stocks, because the chance of a big move is higher. You cannot predict the exact premium without looking at the actual options market, but you can see real prices on any brokerage platform that offers options trading.

Puts versus other ways to protect a stock position

If you own a stock and want to limit losses, you have other choices besides buying a put. You can set a stop-loss order, which automatically sells your shares if the price falls to a certain level — but this does not may provide you will get that price in a fast-moving market. You can sell the stock outright and move the money elsewhere. You can also buy a put spread, where you buy a put at one strike price and sell a put at a lower strike price, reducing the premium you pay but also capping your protection.

A protective put is the most straightforward insurance, but it costs money upfront. A stop-loss order costs nothing but offers no may provide. The right choice depends on how much protection you want, how much you are willing to pay, and how long you plan to hold the stock.

Frequently Asked Questions

Can I lose more than the premium I paid for a put?

No. When you buy a put, your maximum loss is the premium you paid upfront. If the stock rises and your put expires worthless, you lose that premium and nothing more. This is one reason buying puts is less risky than selling them.

What does it mean if a put is "in the money"?

A put is in the money when the stock price falls below the strike price. For example, if you own a put with a $50 strike and the stock is trading at $45, your put is $5 in the money. The deeper in the money a put is, the more it is worth.

Do I have to own the stock to buy a put?

No. You can buy a put on any stock without owning it, betting that the price will fall. However, most individual investors buy puts to protect stocks they already own. Buying puts without owning the stock is a more speculative strategy.

What happens if I exercise my put?

If you exercise a put, you sell 100 shares of the underlying stock at the strike price. The shares must come from your brokerage account. If you do not own the shares, you cannot exercise the put — you can only sell the put contract itself to another investor.

How long can I hold a put?

You can hold a put until its expiration date. Most standard options expire on the third Friday of each month, though some brokerages offer weekly or longer-dated options. Once expiration passes, the put no longer exists and you cannot exercise it.