What an options contract actually is

An options contract is a legal agreement between two people: a buyer and a seller. The buyer pays a fee (called a premium) for the right—but not the obligation—to buy or sell a specific stock at a specific price on or before a specific date. The seller collects that premium and takes on the obligation to complete the trade if the buyer decides to exercise the contract.

Think of it like a reservation at a restaurant. You pay a small fee to hold a table at a set price for a certain night. If you show up, the restaurant must honor that price. If you don't show up, you lose the fee but owe nothing else. The restaurant keeps the fee either way.

The stock price, the contract price (called the strike price), and the expiration date are all locked in when you buy the contract. Those three things determine whether the contract becomes valuable or worthless as time passes and the stock price moves.

Key Takeaways

  • A call option gives you the right to buy a stock at a set price; a put option gives you the right to sell a stock at a set price.
  • You pay a premium upfront to buy an option, and that premium is the most you can lose on that trade.
  • The strike price is the price at which you can buy or sell the stock if you exercise the option, and it stays the same for the life of the contract.
  • Options expire on a set date, and after that date the contract is worthless if you have not used it.
  • Most options traders close their position by selling the contract to someone else before expiration, rather than actually buying or selling the stock.

Calls and puts: the two types of options

There are only two kinds of options contracts. A call option gives you the right to buy a stock at the strike price. A put option gives you the right to sell a stock at the strike price.

If you buy a call on Apple stock with a strike price of $150, you have the right to buy 100 shares of Apple at $150 per share anytime before the expiration date—even if Apple's stock price has climbed to $200. If you buy a put with a strike price of $150, you have the right to sell 100 shares at $150 per share anytime before expiration, even if the stock has fallen to $100.

Calls are used when you expect a stock price to rise. Puts are used when you expect a stock price to fall. But owning the option does not mean you must exercise it. If the stock price moves against you, you straightforward let the contract expire and lose only the premium you paid.

How the premium works and what it depends on

The premium is the price you pay to buy an option contract. It is not the same as the strike price. The strike price is where you can buy or sell the stock; the premium is what you pay for the right to do so.

The premium changes based on four main factors. First, how far the stock price is from the strike price right now. A call option with a strike price of $150 costs more when the stock is trading at $160 than when it is trading at $140, because it is already closer to being profitable. Second, how much time is left before expiration. An option expiring in three months costs more than an identical option expiring in three weeks, because there is more time for the stock to move in your favor. Third, how volatile the stock is. Stocks that swing wildly in price make options more valuable because bigger moves are more likely. Fourth, interest rates and dividends, which have smaller effects.

You can see all these prices on your brokerage platform. Each stock has a chain of available options—different strike prices and expiration dates—with a bid price (what buyers will pay) and an ask price (what sellers want). You pay the ask price when you buy and receive the bid price when you sell.

Strike price and expiration date: the two fixed terms

Every options contract has a strike price and an expiration date printed into it. These do not change. If you buy a call with a $150 strike price expiring in March, that strike price and that March date are locked in for the life of the contract.

The strike price is the price at which you can exercise the option. If you own a call with a $150 strike and the stock is trading at $180, you can buy 100 shares at $150 each—a $30-per-share profit before you account for the premium you paid. If the stock is trading at $140, the option is worthless to exercise, and you would not use it.

Expiration dates are standardized. Most stocks have options that expire on the third Friday of each month, though some brokerages also offer weekly expirations. After the expiration date passes, the contract ceases to exist. If you have not exercised it or sold it, it becomes worthless.

How traders actually make money: buying and selling the contract itself

Most options traders never actually buy or sell the underlying stock. Instead, they buy and sell the option contract itself, the same way you might buy and sell a concert ticket. You buy the ticket for $50, the price rises to $80, and you sell it to someone else for $75—you never attend the concert, but you made $25.

When you buy a call option for $3 per share (the premium), you control the right to buy 100 shares. If the stock rises and that same call option is now worth $7 per share, you can sell the contract to another trader for $7 and pocket the $4-per-share difference. You never owned the stock. You owned the contract, and you sold it for more than you paid.

This is why most options positions close before expiration. The contract loses value as the expiration date approaches, so traders close their position—sell what they bought or buy back what they sold—to lock in a profit or limit a loss. Only a small fraction of options are actually exercised, meaning the buyer actually buys or sells the stock.

What happens at expiration

On the expiration date, any option that is in-the-money (profitable to exercise) is automatically exercised by most brokerages. If you own a call with a $150 strike and the stock is trading at $160 at expiration, your broker will buy 100 shares at $150 and deposit them into your account. You are charged for those shares at the strike price, not the market price.

If an option is out-of-the-money (not profitable to exercise), it straightforward expires worthless. If you own a call with a $150 strike and the stock is trading at $140 at expiration, the contract disappears. You lose the premium you paid, but you owe nothing else.

If you do not want your option to be automatically exercised—for example, because you do not have the cash to buy the stock or do not want to own it—you must close the position before expiration by selling the contract. This is why traders watch their expiration dates closely.

Leverage and risk: why options can amplify gains and losses

Options are leveraged instruments. You control 100 shares of stock by paying a premium that is much smaller than the cost of buying those shares outright. If a stock is trading at $100 per share, buying 100 shares costs $10,000. Buying a call option on those 100 shares might cost $200 to $500 depending on the strike price and expiration date.

This leverage cuts both ways. If the stock rises 10 percent to $110, your $10,000 stock investment gains $1,000 (a 10 percent return). But your $300 option investment might gain $1,000 or more (a 300 percent return or higher), because the option's value rises faster than the stock price when the stock moves in your favor. That is the appeal of options.

The downside is equally sharp. If the stock falls, your option loses value faster than the stock does. If the stock falls 10 percent and your option expires worthless, you lose 100 percent of your premium. You cannot lose more than the premium you paid—that is the maximum loss on a long option—but losing your entire investment on a single trade is possible and common for new traders.

Frequently Asked Questions

What does "in the money" and "out of the money" mean?

An option is in-the-money when it would be profitable to exercise right now. A call with a $150 strike is in-the-money if the stock is trading above $150. A put with a $150 strike is in-the-money if the stock is trading below $150. Out-of-the-money means the opposite—exercising would lose money, so you would not do it.

Can I lose more money than I paid for the option?

No, not on a long option (one you bought). The most you can lose is the premium you paid. If you sold an option (a short position), your losses can be much larger or theoretically unlimited, which is why selling options is riskier than buying them.

Do I need to own the stock to buy a put option?

No. You can buy a put on any stock, whether you own it or not. A put gives you the right to sell at the strike price, but you do not need to own the shares beforehand. If you exercise, you can buy the shares at market price and when ready sell them at the strike price, or your broker can handle the mechanics.

What happens if I buy an option and forget about it until after expiration?

If your option is in-the-money, most brokerages automatically exercise it, which means you will buy or sell the stock at the strike price. If it is out-of-the-money, it straightforward expires worthless and disappears from your account. Either way, you cannot trade it after expiration. Set calendar reminders for expiration dates to avoid surprises.

Why would I sell an option instead of just holding it until expiration?

Options lose value as expiration approaches, even if the stock price does not move. If you bought a call for $3 and it is now worth $2 with two weeks left, selling locks in your remaining value. Holding until expiration risks losing the rest. Most traders close positions early to manage this time decay.