What an option actually is

An 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 pay a small upfront cost, called the premium, to own that right. The person on the other side of the contract collects that premium and takes on the obligation to sell or buy the stock if you decide to use your right.

Think of it like paying for an insurance policy on a stock price. If you buy a call option on Apple stock, you are paying for the right to buy Apple at, say, $150 per share anytime before the option expires. If Apple's stock price jumps to $160, your option is worth money — you can buy at $150 and when ready sell at $160. If Apple stays at $140 or drops, your option expires worthless and you lose only the premium you paid upfront.

Options are traded on exchanges like the Chicago Board Options Exchange (CBOE). Each contract represents the right to buy or sell 100 shares of the underlying stock. So when you see an option price quoted at $2, you actually pay $200 to control 100 shares ($2 × 100).

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 own the option, and that is the maximum you can lose if the option expires worthless.
  • Options have an expiration date — they stop existing on that date, and any right you had disappears.
  • The strike price is the price at which you can buy or sell the stock if you exercise your option.
  • Options let you control 100 shares of stock with a much smaller cash outlay than buying the stock itself.

Calls and puts: the two types of options

There are only two kinds of options: calls and puts. A call option gives you the right to buy the stock. A put option gives you the right to sell the stock. Most traders buy calls when they think a stock price will rise, and buy puts when they think a stock price will fall.

When you buy a call, you are betting the stock will go up. You pay the premium, and if the stock rises above your strike price plus the premium you paid, you make money. For example: you buy a call on Microsoft with a strike price of $300, paying a $5 premium. Microsoft rises to $310. You can exercise the option, buy 100 shares at $300, and sell them at $310 for a $10 per share gain — minus the $5 premium you paid, leaving you $5 per share ahead (or $500 total on the contract).

When you buy a put, you are betting the stock will go down. You pay the premium, and if the stock falls below your strike price minus the premium you paid, you make money. You buy a put on Tesla with a strike price of $200, paying a $4 premium. Tesla falls to $190. You can exercise the option, sell 100 shares at $200 (even though the market price is $190), and pocket the difference — minus the $4 premium you paid.

Strike price and expiration date

The strike price is the price at which you can buy (for a call) or sell (for a put) the stock if you use your option. It is fixed when you buy the option and does not change. The stock price moves around in the market, but your strike price stays the same for the life of the contract.

The expiration date is the last day you can exercise your option. After that date, the option ceases to exist. Most stock options expire on the third Friday of each month, though some expire weekly. If you own an option that expires on a Friday and the stock price has not moved in your favor, you must decide by that Friday whether to exercise it, sell it to someone else, or let it expire.

The relationship between the current stock price and the strike price determines whether an option has value. If you own a call with a $100 strike price and the stock is trading at $105, your option is in the money — it has intrinsic value. If the stock is at $95, your option is out of the money — it has no intrinsic value, though it may still have time value if expiration is weeks away.

How premiums are set

The premium — the price you pay for the option — is determined by supply and demand on the options exchange, just like stock prices. But several factors push that price up or down. The farther away the expiration date, the higher the premium, because there is more time for the stock to move in your favor. The closer the strike price is to the current stock price, the higher the premium. And the more volatile the stock (the more its price swings), the higher the premium, because there is a greater chance the option will end up in the money.

You do not negotiate the premium. You see the bid price (what buyers are offering) and the ask price (what sellers are asking), and you choose whether to buy at the ask or sell at the bid. The difference between bid and ask is called the spread. A tight spread means you can get in and out cheaply; a wide spread means it costs more to trade.

Exercising an option or letting it expire

When your option reaches a price you like, you have three choices: exercise it, sell it to someone else, or hold it and hope it moves further in your favor.

If you exercise a call option, you pay the strike price and receive 100 shares of the stock. If you exercise a put option, you deliver 100 shares and receive cash at the strike price. Most retail traders never exercise options. Instead, they sell the option contract itself to another trader before expiration, locking in a profit or loss without ever touching the underlying stock.

If you let an option expire without exercising it or selling it, the contract straightforward disappears. If it expired out of the money (worthless), you lose the entire premium you paid. If it expired in the money, you may have missed a profit — but you still only lose what you paid upfront.

Why traders use options instead of buying stock

Options let you control a large position with a small amount of cash. If you have $500, you cannot buy 100 shares of a $100 stock. But you might be able to buy one call option contract on that stock for $200 or $300, controlling the same 100 shares. If the stock rises 10 percent, your option might rise 50 percent or more, because you are controlling the same number of shares with less money at risk.

Options also let you profit from a stock falling without borrowing shares. With a put option, you do not need a margin account or a short sale — you straightforward buy the put and profit if the stock drops.

But this leverage cuts both ways. Because you are controlling more shares with less money, a small move against you can wipe out your entire premium. If you buy a call for $200 and the stock drops 5 percent, your option might be worth $50 or zero, losing 75 to 100 percent of your money in days.

Common mistakes when starting with options

New traders often buy options that are far out of the money, betting on a huge stock move. These options are cheap because they are unlikely to profit. The odds are against you, and most of these bets expire worthless. Buying options closer to the current stock price costs more but has a much higher probability of profit.

Another mistake is holding an option all the way to expiration. As expiration approaches, the option loses value faster — a process called time decay. If you bought an option three months ago and it has not moved much, selling it two weeks before expiration might recover only 10 percent of what you paid, even if the stock is still near your strike price. Selling earlier, when there is still time value left, often makes more sense than waiting.

New traders also underestimate how much the premium can swing. An option that costs $200 today might cost $500 tomorrow if the stock moves sharply, or $50 if it moves the wrong way. The premium is not stable like a stock price — it is constantly repriced based on the stock's movement and how much time is left.

Frequently Asked Questions

What is the maximum I can lose if I buy an option?

The maximum loss is the premium you paid upfront. If you buy a call for $200 and the stock drops to zero, you lose $200 — not more. You cannot lose money on the underlying stock because you never owned it. This is why options are sometimes used as a way to limit risk compared to buying stock on margin.

Can I sell an option I do not own?

Yes. This is called selling to open, or writing an option. You collect the premium upfront, but you take on the obligation to buy or sell the stock if the buyer exercises. Selling options is riskier than buying them because your potential loss is much larger. Most brokers require a margin account and experience before allowing you to sell options.

What happens if I own a call and the stock gets bought by another company?

The option contract usually adjusts or is settled based on the acquisition price. If the acquiring company pays $150 per share and your call has a $140 strike price, your option is worth at least $10 per share. The exact settlement depends on the deal terms and your broker's rules — contact your broker before the deal closes to understand what will happen.

Do I need a lot of money to start trading options?

Most brokers require a minimum account balance to trade options, often $2,000 to $25,000 depending on the broker and the type of options you want to trade. Some brokers have lower minimums for buying options only (not selling them). Check your broker's requirements before opening an account.

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 profit. Strike prices far from the current price cost less but rarely profit. Most traders choose a strike price 5 to 10 percent away from the current stock price, balancing cost against probability. Your broker's options chain shows all available strike prices and their premiums so you can compare.