What a Call Option Is and How Stock Investors Use It

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

When you buy a call option, you are paying for the right — not the obligation — to purchase 100 shares of a stock at a price you agree to now. That agreed price is called the strike price. The date by which you must decide is called the expiration date. If the stock price rises above your strike price before expiration, your call becomes valuable because you can buy the stock cheaper than the market price and sell it for a profit. If the stock price stays flat or falls, your call loses value and you can let it expire worthless.

Calls are traded on options exchanges, just like stocks are traded on stock exchanges. You buy and sell them through the same brokerage account you use for stocks. One call contract always represents the right to buy 100 shares, so if you see a call priced at $3, you pay $300 to buy that contract ($3 × 100 shares).

Key Takeaways

• A call option gives you the right to buy 100 shares of a stock at a set price (the strike price) before a set date (expiration).
• You profit on a call if the stock price rises above the strike price before expiration, because you can buy low and sell high.
• The price you pay upfront for a call is called the premium, and you lose that money if the stock does not rise above the strike price.
• Calls are riskier than owning the stock outright because your money is tied to a specific price and a specific date.
• Most individual investors who buy calls are betting the stock will rise; most who sell calls are collecting income from investors making that bet.

How the money works when you buy a call

Suppose you buy a call on Apple stock with a strike price of $150 and an expiration date three months away. You pay a premium of $5 per share, or $500 total, for that contract. If Apple rises to $160 before expiration, your call is now worth at least $10 per share (the difference between the market price and your strike price), so you can sell the contract for a profit. You keep the difference between what you sold it for and the $500 you paid.

If Apple stays at $145 or falls to $140, your call expires worthless. You lose the entire $500 premium you paid. You do not own any Apple shares, and you do not owe anything beyond the premium you already paid. Your loss is capped at the money you spent upfront.

Most people who buy calls never actually buy the 100 shares. They buy the call, wait for the stock to rise, then sell the call contract itself to someone else for a profit. This is called closing the position. You can close a call at any time before expiration, not just on the expiration date.

Why investors buy calls instead of buying the stock

A call lets you control 100 shares of a stock with far less money than buying the stock outright. If Apple is trading at $150, buying 100 shares costs $15,000. Buying a call with a $150 strike price might cost $500. That $500 is your maximum loss, whereas if you bought the stock and it fell to $100, you would lose $5,000.

This leverage — controlling more shares with less money — is the main reason people buy calls. If you are right about the direction and timing, your percentage gain is much larger. If Apple rises to $160, your $500 call might be worth $1,000, which is a 100% return on your $500. If you had bought the stock at $150, a rise to $160 is only a 6.7% return.

The tradeoff is that calls expire. Your stock does not. If you buy Apple stock at $150 and it rises to $160 five years later, you still make money. If you buy a call that expires in three months and Apple does not rise above $150 in that time, you lose everything you paid for the call, even if Apple rises to $160 a year later.

What happens if you sell a call

When you sell a call, you are taking the other side of the bet. Someone else pays you a premium for the right to buy a stock from you at the strike price. If the stock stays below the strike price, the buyer lets the call expire worthless and you keep the entire premium as profit. If the stock rises above the strike price, the buyer exercises the call and you must sell them 100 shares at the strike price, even though the stock is now worth more.

Most people who sell calls own the stock already. They sell a call on stock they already hold, collect the premium, and hope the stock does not rise above the strike price. If it does, they sell their shares at the strike price (which they agreed to) and keep the premium on top. This strategy is called a covered call because the shares are already in your account, so you are not forced to buy shares you do not own.

Selling a call without owning the stock is called a naked call and is much riskier. If the stock rises sharply, you are forced to buy 100 shares at the market price and sell them at the lower strike price, locking in a loss. Your loss is theoretically unlimited because a stock price can rise indefinitely.

The role of expiration dates and strike prices

Every call has an expiration date, usually the third Friday of the month. Common expiration dates are 30 days, 60 days, 90 days, and longer. The closer the expiration date, the less time the stock has to move, so calls with near-term expirations are cheaper than calls with the same strike price months away.

The strike price determines how far the stock must rise for you to make money. A call with a strike price close to the current stock price is cheaper but requires less upward movement to be profitable. A call with a strike price far above the current stock price is cheaper still but requires a larger move to profit. There is no single "best" strike price — it depends on how much you want to spend and how much you expect the stock to move.

Risks specific to calls

The biggest risk is that you lose your entire premium if the stock does not move the way you expected or does not move fast enough. Unlike owning a stock, where you can wait years for a recovery, a call expires on a specific date. If you are wrong about timing, you lose money even if you were right about direction.

Calls are also sensitive to factors beyond the stock price. The premium you pay depends not just on how far the stock might move, but on how volatile the stock is, how much time is left until expiration, and interest rates. A stock can stay flat and a call can still lose value simply because time is passing and expiration is getting closer. This is called time decay.

Calls are also more complex to trade than stocks. You need approval from your broker to trade options, and different brokers have different rules about which options strategies they allow. Selling calls, especially naked calls, requires higher approval levels and carries risks that can wipe out your account if you are not careful.

How calls fit into a portfolio

Most individual investors who use calls are either speculating on short-term price moves or generating income from stocks they already own. Speculators buy calls when they think a stock will rise sharply in a short window. Income investors sell covered calls on stocks they plan to hold anyway, collecting premiums as extra return.

Calls are not a core holding like stocks or bonds. They are a tool for a specific bet or strategy. If you are building a long-term portfolio, you probably do not need calls at all. If you are trying to amplify gains on a stock you are bullish on, or collect extra income from a stock you already own, calls may make sense as a small part of your overall strategy.

Frequently Asked Questions

What is the difference between a call and a put?

A call gives you the right to buy a stock at a set price. A put gives you the right to sell a stock at a set price. Investors buy calls when they expect a stock to rise and buy puts when they expect it to fall. Both are options contracts that expire on a specific date.

Can I lose more money than I paid for a call?

If you buy a call, no. Your loss is capped at the premium you paid. If you sell a naked call, yes — your loss is theoretically unlimited because the stock price can rise indefinitely and you are forced to buy shares at the market price to sell them at the lower strike price.

Do I have to exercise a call if the stock rises above the strike price?

No. You have the right to exercise, not the obligation. Most people who profit on a call sell the contract itself rather than exercising it and buying the shares. Selling the contract is usually more profitable and simpler than buying 100 shares and selling them separately.

How do I know what strike price to choose?

It depends on your outlook and budget. A strike price close to the current stock price is more expensive but requires less upward movement to profit. A strike price far above the current price is cheaper but requires a bigger move. Start by deciding how much you want to spend and how much you expect the stock to move, then choose a strike that matches both.

What brokers let me trade calls?

Most major brokers including Fidelity, Charles Schwab, E-Trade, and Interactive Brokers offer options trading. You will need to request options approval, which usually takes a few days. Different brokers have different approval levels — some restrict you to buying calls and covered calls, while others allow more complex strategies.