Options Trading: How Calls and Puts Actually Work

An option is a contract. It gives you the right, but not the obligation, to buy or sell 100 shares of a stock at a fixed price, on or before a fixed date. You pay a premium for that right.

That structure is what makes options useful. You can define your risk precisely, profit from a stock falling without short selling it, or generate income from shares you already hold. It's also what makes them the fastest way to lose money in the market, because you can be completely right about direction and still lose everything.

The four things that define every option

1. Type: a call (right to buy) or a put (right to sell).
2. Strike price: the fixed price at which you may transact.
3. Expiry date: after which the contract ceases to exist.
4. Premium: what the contract costs, quoted per share, so multiply by 100.

A "TSLA 250 call expiring March 20" is the right to buy 100 Tesla shares at $250 any time before March 20. If it's quoted at $4.20, one contract costs you $420.

Calls and puts

	Buying a call	Buying a put
You expect	The stock to rise	The stock to fall
You gain the right to	Buy 100 shares at the strike	Sell 100 shares at the strike
Maximum loss	The premium paid	The premium paid
Maximum gain	Theoretically unlimited	Strike minus premium, per share
Works against you	Time decay	Time decay

Look at the last row. Whichever direction you pick, time is the opponent for a buyer. That asymmetry sits at the heart of options trading, and it's the part the marketing leaves out.

Premium is about more than direction

An option's price has exactly two components:

• Intrinsic value: what the contract would be worth if exercised right now. A $250 call with the stock at $268 has $18 of intrinsic value. If the stock is below $250, intrinsic value is zero.
• Extrinsic value: everything else. It's what the market charges for the possibility that the option becomes more valuable before expiry, and it's driven by the time remaining and by implied volatility.

Extrinsic value decays to zero at expiry, always. Every day you hold, a little of it evaporates, and the decay accelerates sharply in the final weeks. That's how a stock can rise while your call loses money. The gain in intrinsic value was smaller than the loss in extrinsic value.

Implied volatility, and why options get cheaper after good news

Implied volatility is the market's expectation of future movement, and it's baked into the premium. When a big event is coming, earnings or an FDA decision say, IV rises and options get expensive. Once the event passes, IV collapses.

The result catches people out constantly. You buy a call before earnings, the company beats, the stock jumps 6%, and your option is worth less than you paid. The move was already priced in, and the volatility crush took more than the direction gave you. That's IV crush, and it's why buying short-dated options into earnings is close to a coin flip with a negative edge attached.

The Greeks, briefly

The Greeks measure how an option's price responds to each variable.

Greek	Measures	What it means day to day
Delta	Sensitivity to the stock's price	0.50 delta means the option moves about $0.50 per $1 of stock
Gamma	How fast delta changes	High near the strike and near expiry; makes positions swing violently
Theta	Time decay per day	Negative for buyers, positive for sellers; your daily rent
Vega	Sensitivity to implied volatility	Why your option lost value after earnings despite being right

You don't need to calculate any of these. You do need to know that four separate forces act on your position, and only one of them is whether you picked the right direction.

Strategies, from safest to least

• Covered call: you own 100 shares and sell a call against them. Collects premium, caps your upside. The most conservative options strategy that exists.
• Cash-secured put: you sell a put while holding enough cash to buy the shares if you're assigned. You get paid to agree to buy a stock lower. Only sensible on stock you'd genuinely be happy to own.
• Long call / long put: defined risk, but time decay works against you every day. Give yourself more expiry than you think you need.
• Vertical spread: buy one option, sell another further out. Caps both risk and reward, and reduces the cost of time decay.
• Naked short options: collecting premium with undefined risk. Not a beginner strategy under any circumstances.

Before you trade your first contract

1. Learn the underlying first. If you can't trade the shares profitably, options won't fix that. They'll amplify it. Start with stock trading.
2. Understand assignment. Know what happens if you're assigned, and what it will cost you.
3. Buy more time than feels necessary. Most beginner losses come from being right too late.
4. Check liquidity. Wide bid-ask spreads on thin contracts can cost more than the trade makes.
5. Size in dollars, not contracts. One contract controls 100 shares. Apply the same risk rules you would to the equivalent share position.