What Is an Option? A Plain-English Guide
Beginner · 5 min read · Updated April 2026
An option is a contract that pays someone today for the right to buy or sell a stock later, at a price you both agree on now. That’s it. The rest is just names for the moving parts.
The one-sentence version
An option is a deal: someone pays cash today for the right — but not the obligation — to buy or sell 100 shares of a specific stock at a specific price before a specific date.
That’s an option contract — a price agreement with an expiration date.
The four moving parts
Every option contract has the same four ingredients. Once you know these, every strategy is just a combination.
1. The underlying stock
The stock the contract is about — Apple (AAPL), SPY, Tesla (TSLA), etc. One contract always covers 100 shares of that stock.
2. The strike price
The agreed-upon price. If AAPL is trading at $187 and you’re looking at a $195 call, $195 is the strike — the price at which shares would change hands if the contract is used.
3. The expiration date
The deadline. After this date, the contract ceases to exist. Options expire weekly, monthly, or longer.
4. The premium
The cost of the contract — paid upfront by the buyer to the seller. Quoted per share but traded in 100-share contracts. A premium of $2.40 means one contract costs (or pays) $240.
Calls and puts — the two flavors
There are exactly two kinds of options. Everything else is a combination of these.
A call = the right to buy
Call buyers think the stock will go up. If AAPL is $187 and you buy a $195 call, you’re betting AAPL rallies past $195 before expiration. If it does, you can either exercise the right to buy at $195 (and sell at the higher market price) or sell the call itself for a profit.
A put = the right to sell
Put buyers think the stock will go down — or want insurance on shares they own. A $180 put on AAPL gives you the right to sell 100 shares at $180 even if the market price drops to $160. That’s portfolio insurance.
Buyer vs. seller — two sides of every trade
For every option there’s a buyer paying the premium and a seller collecting it. The buyer has a right; the seller has an obligation to deliver if the right is used. That distinction drives every strategy.
Buying options
Pay premium today, hope the stock moves your way. Max loss is the premium paid. Upside can be large if the stock moves hard.
Selling options
Collect premium today, hope the stock stays put or moves in a certain direction. Max profit is the premium collected. Risk depends on whether you’re covered (own the underlying stock or have cash set aside) or naked (not).
A real example
AAPL is $187. You buy one $195 call expiring in 35 days for $2.40 per share — $240 total. Two possible endings:
- AAPL closes at $205. Your call is worth at least $10 per share ($1,000 per contract). You made ~$760 after the $240 cost.
- AAPL closes at $190. Your call expires worthless. You lose the full $240.
Where to go next
Now that you know what options are, the next step is learning a strategy — a specific combination of buying or selling options that fits a specific outlook. The safest starting point for most beginners who own stock is the covered call.
Common questions
Are options risky?
It depends entirely on which strategy you use. Buying options can lose you the entire premium paid. Selling options covered by stock you own (like covered calls) caps your profit but not your risk of the stock falling. Selling naked options has theoretically unlimited loss potential. “Options” as a category isn’t the right risk frame — the specific strategy is.
How much does one options contract cost?
The premium varies with the stock price, time to expiration, and implied volatility. A contract covers 100 shares, so a $2.40 premium per share means $240 to buy or collect for one contract.
What's the difference between a call and a put?
A call gives the right to buy shares at the strike price. A put gives the right to sell shares at the strike price. Call buyers bet on the stock going up; put buyers bet on it going down or want protection against a drop.
Next in Start Here · The Basics
Covered calls, explained
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