A call option gives you the right to buy a stock at a set price by a certain date

A call option is a contract that lets you purchase shares of a stock at a fixed price — called the strike price — on or before an expiration date. You are not required to buy; you have the right to buy if you choose to. The person or entity selling you the call option collects a fee upfront, called the premium, whether or not you ever exercise that right.

Think of it like a reservation at a restaurant. You pay a small fee to hold a table at a set price for a specific night. If the restaurant becomes very popular and prices go up, you benefit from your locked-in rate. If it becomes less popular and prices drop, you can walk away and lose only the reservation fee.

Call options are traded on options exchanges, most commonly through your brokerage account. They are separate from owning the stock itself — you can own a call option without owning any shares of the underlying company.

Key Takeaways

  • A call option is a contract that gives you the right (but not the obligation) to buy a stock at a fixed strike price before the expiration date.
  • You pay a premium upfront to buy a call option, and that premium is the most you can lose if the stock price falls.
  • If the stock price rises above the strike price plus the premium you paid, you can profit by exercising the option or selling it to someone else.
  • Call options expire on a specific date, after which the contract becomes worthless if you have not used it.
  • You can use call options to bet on a stock price rising, to lock in a purchase price, or to generate income by selling calls against stocks you own.

How the strike price and premium work together

The strike price is the price at which you can buy the stock if you exercise the option. This price is set when the contract is created and does not change, even if the stock price moves. For example, a call option might give you the right to buy Apple stock at $150 per share.

The premium is what you pay to own the call option itself. Premiums vary based on how likely the option is to become profitable. If a stock is trading at $140 and you buy a call with a $150 strike price, the premium might be $2 per share (or $200 for a contract covering 100 shares, since one options contract typically represents 100 shares). If the stock is trading at $160, the same $150 strike call might cost $12 per share because it is already in-the-money.

Your break-even point is the strike price plus the premium you paid. In the first example, you break even if Apple reaches $152 ($150 strike + $2 premium). Below that price, you lose money. Above it, you profit.

What happens when a call option expires

Every call option has an expiration date, typically the third Friday of the month for standard options. On that date, the contract expires and becomes worthless if you have not exercised it. You cannot use an expired call option to buy the stock at the strike price.

Before expiration, you have three choices: exercise the option (buy the stock at the strike price), sell the option to someone else, or let it expire worthless. Most traders sell their options before expiration rather than exercising them, because selling captures whatever profit remains in the contract without requiring you to buy 100 shares of stock.

If you own a call option that is "in-the-money" (the stock price is above the strike price) at expiration, some brokerages will automatically exercise it for you, meaning you will own the shares. Check your brokerage's policy on automatic exercise, because this can tie up cash or margin in your account.

When you profit or lose money on a call option

You profit on a call option when the stock price rises above your break-even point (strike price plus premium paid). The higher the stock goes, the more your option is worth. If you sell the option before expiration, you pocket the difference between what you paid and what you sold it for.

You lose money if the stock price stays below your break-even point. Your maximum loss is the premium you paid upfront. If you paid $200 for a call option and the stock never rises enough to make it profitable, you lose that $200 and nothing more — you are not on the hook for additional losses.

The seller of the call option (the person who collected the premium) profits if the stock stays below the strike price, because the option expires worthless and they keep the premium. If the stock rises sharply, the seller's loss can be large, especially if they do not own the underlying stock.

The difference between buying and selling call options

Buying a call option means you pay a premium and gain the right to buy stock at the strike price. Your risk is limited to the premium you paid. Your profit potential is unlimited as the stock price rises. Buyers typically use calls when they expect a stock to rise.

Selling a call option (also called "writing" a call) means you collect a premium from someone else and take on the obligation to sell them shares at the strike price if they exercise. Your profit is limited to the premium you collect. Your loss can be large if the stock price rises sharply, unless you own the stock already (a "covered call"). Sellers typically use calls when they expect a stock to stay flat or fall, or when they want to generate income from stock they already own.

Most beginning traders buy calls rather than sell them, because the risk is clearer and the maximum loss is known upfront.

Why traders use call options instead of buying stock

Call options require less money upfront than buying stock. If you want to control 100 shares of a $150 stock, buying the stock costs $15,000. Buying a call option on that stock might cost $200 to $500, depending on the strike price and expiration date. This leverage means a small move in the stock price can produce a large percentage gain on your option investment.

Call options also let you profit from a stock rising without owning it. You do not have to hold the shares, pay dividends, or deal with voting rights. You straightforward own the right to buy at a set price, and you can sell that right to someone else whenever you want.

Some traders use call options to hedge other positions or to bet on a stock rising over a specific time frame. Others use them to lock in a purchase price for a stock they plan to buy anyway, similar to placing a reservation.

Common mistakes people make with call options

Holding a call option until expiration is risky. As expiration approaches, the option loses value quickly if the stock has not moved above the strike price. Most traders sell their options with time remaining, even if the option is not yet profitable, to avoid losing the entire premium.

Underestimating how much a stock needs to move is another common error. If you pay a $3 premium for a call option, the stock needs to rise $3 just for you to break even. Many traders buy options expecting a small move, then watch the option expire worthless because the stock did not move enough.

Selling call options without understanding the risk is dangerous. If you sell a call on a stock you do not own, your loss is theoretically unlimited if the stock price soars. Even if you own the stock, selling calls means you cap your upside if the stock rises sharply past the strike price.

Frequently Asked Questions

Can I lose more than the premium I paid for a call option?

No, if you buy a call option, your maximum loss is the premium you paid upfront. If the stock price falls to zero, your option expires worthless and you lose only what you invested in the premium. However, if you sell a call option, your losses can be much larger.

What does "in-the-money" mean for a call option?

A call option is in-the-money when the stock price is above the strike price. For example, if you own a call with a $50 strike price and the stock is trading at $55, your option is in-the-money by $5. This does not mean you have made a profit yet — you still need to account for the premium you paid.

Should I exercise my call option or sell it?

Most traders sell their call options rather than exercise them. Selling captures the remaining time value in the contract and avoids tying up cash to buy 100 shares. Exercise only if you actually want to own the stock at that price, or if the option is about to expire and is deeply in-the-money.

How do I know what strike price to choose?

Strike prices closer to the current stock price cost more but have a higher chance of becoming profitable. Strike prices further away cost less but require a larger stock move to profit. Choose based on how much you expect the stock to move and how much risk you are willing to take.

Can I sell a call option I bought?

Yes. You can sell any call option you own to another trader before expiration. The price you receive depends on the stock price, time remaining, and market demand. This is how most call option trades end — with a sale, not an exercise.