What a trading option is

A trading option is a contract that gives you the right—but not the obligation—to buy or sell a specific stock at a set price by a certain date. You are not buying the stock itself. You are buying the right to make that transaction later, and you pay a smaller amount upfront called the premium to hold that right.

The two basic types are call options and put options. A call option lets you buy a stock at a fixed price. A put option lets you sell a stock at a fixed price. The fixed price is called the strike price. The date by which you must act is called the expiration date.

Options are traded on exchanges like the Chicago Board Options Exchange (CBOE). You buy and sell them through a brokerage account, the same way you would trade stocks. The price of an option changes throughout the day based on what other traders are willing to pay for it.

Key Takeaways

  • An option is a contract giving you the right to buy (call) or sell (put) a stock at a set price by a set date, and you pay a premium upfront to own that right.
  • The strike price is the fixed price at which you can buy or sell; the expiration date is when the option stops existing and becomes worthless if you have not used it.
  • Options are leveraged—you control a larger amount of stock value with a smaller upfront payment, which means both gains and losses can be larger than the premium you paid.
  • Most options expire worthless because the stock price never moves in the direction the buyer bet on, so the premium paid is lost entirely.
  • You need a brokerage account that permits options trading, and most brokers require you to pass a brief questionnaire about your experience before opening options permission.

How the strike price and expiration date work together

The strike price is the price at which you have the right to transact. If you buy a call option on Apple stock with a strike price of $150, you have the right to buy Apple shares at $150 each, no matter what the actual market price is when you exercise the option. If Apple stock is trading at $160, you can buy at $150 and immediately sell at $160, pocketing the $10 difference (minus the premium you paid).

The expiration date is when the option ceases to exist. Most stock options expire on the third Friday of the month. After that date, the contract is worthless and you cannot use it. If you own a call option that expires on the third Friday of January and you have not exercised it by then, it is gone. You lose whatever premium you paid for it.

Options that are "in the money"—meaning the stock price has moved in your favor—still have value even if you do not exercise them. You can sell the option contract itself to another trader before expiration and pocket the difference between what you paid and what someone else will pay for it.

Why the premium matters and how leverage works

The premium is the price you pay to own the option contract. It is usually much smaller than the price of the stock itself. For example, you might pay $2 per share for a call option, which means $200 for one contract (since one options contract covers 100 shares). That $200 controls the right to buy 100 shares of stock that might be worth $15,000 or $20,000.

This is leverage: you control a large amount of stock value with a small upfront payment. If the stock moves $5 in your favor, your $200 premium might become worth $700 or $800—a much larger percentage gain than if you had bought the stock outright. But if the stock moves $5 against you, your $200 premium can become worthless. You lose the entire amount you paid.

Because of this leverage, options are riskier than stocks. You can lose 100 percent of your premium, whereas with a stock you would have to hold it all the way to zero to lose everything. Most options expire worthless because the stock price does not move far enough or in the right direction by the expiration date.

Call options versus put options

A call option is a bet that the stock price will go up. You buy a call when you think the stock will rise above the strike price before expiration. If you are right, the option becomes valuable and you can sell it or exercise it. If the stock stays flat or falls, the call loses value and expires worthless.

A put option is a bet that the stock price will go down. You buy a put when you think the stock will fall below the strike price before expiration. If you are right, the put becomes valuable. If the stock rises or stays flat, the put loses value and expires worthless.

You can also sell options you do not own—a strategy called writing or shorting an option. When you sell a call, you are betting the stock will stay flat or fall. When you sell a put, you are betting the stock will stay flat or rise. Selling options is riskier than buying them because your potential loss is theoretically unlimited, whereas buying an option limits your loss to the premium you paid.

What happens when an option expires

On the expiration date, the option contract simply ceases to exist. If you own an option that is "out of the money"—meaning the stock price moved against you—it expires worthless and you lose the premium you paid. There is no refund and no second chance.

If your option is "in the money" at expiration, most brokerages will automatically exercise it for you. If you own a call option with a strike price of $150 and the stock is at $160 at expiration, your broker will buy 100 shares at $150 and add them to your account. You are now holding stock, not an option. If you do not have enough cash in your account to cover the purchase, your broker may sell the option contract instead to raise the cash.

You can also choose to close out an option before expiration by selling it to another trader. This is how most options traders actually make money—by selling the contract for more than they paid, not by exercising it. You do not have to wait until expiration day.

How to start trading options

You need a brokerage account that permits options trading. Most major brokers—Fidelity, Charles Schwab, TD Ameritrade, E*TRADE, Interactive Brokers—offer options. You cannot trade options with a basic cash account; you typically need a margin account or a dedicated options account.

When you request options permission, your broker will ask you to complete a questionnaire about your investment experience, income, and risk tolerance. This is not a test you can fail, but brokers use it to assign you an options approval level. Level 1 usually permits buying calls and puts only. Higher levels permit selling options and more complex strategies. You can request a higher level later if you want to expand what you can trade.

Once you have permission, you can place an options order through your broker's platform the same way you would place a stock order. You specify the stock, the strike price, the expiration date, and whether you are buying or selling. The order goes to the options exchange and is matched with another trader.

Frequently Asked Questions

Do I have to exercise an option if I own it?

No. You have the right to exercise, but you are never required to. Most options traders sell the contract before expiration rather than exercising it. If you let an out-of-the-money option expire, it simply becomes worthless and you lose the premium. If it is in the money, your broker will usually exercise it automatically unless you tell them not to.

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

If you are buying options, no—your maximum loss is the premium you paid. If you are selling options, yes, your loss can be much larger than the premium you received. This is why selling options is considered riskier and usually requires higher approval levels from your broker.

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

For a call option, "in the money" means the stock price is above the strike price. For a put option, "in the money" means the stock price is below the strike price. "Out of the money" is the opposite. An option that is out of the money at expiration is worthless.

How long do options typically last?

Most stock options expire on the third Friday of each month. You can buy options that expire in a few days, weeks, or months ahead. The longer the expiration date, the more expensive the option premium usually is, because there is more time for the stock to move in your favor.

What is the difference between American and European options?

American options can be exercised any time before expiration. European options can only be exercised on the expiration date itself. Most stock options traded in the United States are American. The distinction matters mainly to advanced traders; for most people buying and selling options, it does not change how you trade them.