An option is a contract that gives you the right, but not the obligation, to buy or sell 100 shares of a stock at a fixed price, until a fixed date. You pay a fee for that right. That fee is the most you can lose. Everything else about options is detail on top of that sentence.

The five words you need

• Call: the right to buy 100 shares at the strike. You buy calls when you think the stock goes up.
• Put: the right to sell 100 shares at the strike. You buy puts when you think the stock goes down.
• Strike: the fixed price written into the contract.
• Expiration: the date the contract dies. After that it's worth exactly zero.
• Premium: what you pay for the contract, quoted per share. A premium of $1.50 means the contract costs $150, because it covers 100 shares.

Why traders use them instead of stock

Leverage. To control 100 shares of a $100 stock you'd need $10,000. A call option on the same 100 shares might cost $200. If the stock rises $3, the shares make $300 (3%). The call might rise from $2 to $4, making $200 (100%). Same stock move, wildly different percentage. The catch: if the stock goes nowhere, the stock holder loses nothing and the option holder can lose everything. Leverage cuts both ways, always.

Buying vs selling options

Everything in this path is about buying calls and puts. Selling (writing) options has a very different risk shape: limited gain, potentially large loss. It's a legitimate strategy for later, not a place to start.

An option's premium is made of two pieces. Understand the split and most of the confusing behavior of options suddenly makes sense.

Intrinsic value: what it's worth right now

If the stock is $105 and you hold a $100 call, that call is worth at least $5, because you could exercise it and buy at $100 something worth $105. That $5 is intrinsic value. A $110 call on the same stock has zero intrinsic value: the right to buy at $110 when the stock is $105 isn't worth anything on its own.

• In the money (ITM): has intrinsic value. Calls with strikes below the stock price, puts with strikes above it.
• At the money (ATM): strike roughly equals the stock price.
• Out of the money (OTM): no intrinsic value. Calls above the stock price, puts below it.

Extrinsic value: what you pay for possibility

That $110 call with zero intrinsic value still costs something, maybe $1.20. Why? Because the stock might get above $110 before expiration. That "might" is extrinsic value, also called time value. It depends on two things: how much time is left, and how much the stock tends to move (its volatility). More time and more volatility mean more possibility, so more extrinsic value.

Extrinsic value is the part that melts. Every day that passes, some of the possibility is gone, and at expiration extrinsic value is exactly zero. What's left is intrinsic only. This is the single most important thing for a day trader to understand, because you are almost always buying extrinsic value and racing the clock.

Implied volatility: the price of fear

Implied volatility (IV) is the market's guess about how wild the stock will be. When everyone expects a big move (earnings tomorrow, a court ruling, a market panic), IV is high and every option is expensive. When things are calm, IV is low and options are cheap. Buying options when IV is high is like buying umbrellas during a storm: you pay up. When the storm passes and IV drops, your option loses value even if the stock didn't move. That's IV crush.

The Greeks are four numbers your broker shows next to every option. They answer four questions: How much does this move when the stock moves? Does that change? How much do I lose per day just waiting? How much does fear affect the price? Learn them as questions, not as math.

Delta: how much the option moves per $1 in the stock

A delta of 0.50 means the option gains about $0.50 (so $50 per contract) when the stock rises $1. Calls have positive delta from 0 to 1; puts have negative delta from 0 to −1. Delta also works as a rough probability: a 0.30 delta option has roughly a 30% chance of finishing in the money.

• Deep in the money: delta near 1. Moves almost dollar-for-dollar with the stock. Expensive, behaves like stock.
• At the money: delta near 0.50. The balance point most day traders prefer.
• Far out of the money: delta near 0.10. Cheap, but the stock has to move a lot before it responds. Lottery tickets.

Gamma: delta changes as the stock moves

Gamma is how fast delta changes. An at-the-money option close to expiration has huge gamma: a $1 move in the stock might take its delta from 0.50 to 0.75. That's why short-dated options explode in value on a fast move, and why they collapse just as fast the other way. Gamma is the fuel behind both the wins and the disasters in options day trading.

Theta: what you lose every day by waiting

Theta is the daily cost of holding. A theta of −0.08 means the option loses about $0.08 ($8 per contract) each day, with nothing else changing. Theta accelerates as expiration approaches: the last week burns far faster than the previous month. An option with three days left can lose a third of its value overnight while the stock does nothing.

Vega: sensitivity to fear

Vega is how much the option price changes for a 1-point change in implied volatility. Long-dated options have big vega; same-week options have small vega. For a day trader the practical lesson is: know whether IV is high or low before you buy, and never hold a long option into an event where IV will collapse.

The options chain is the menu: every strike and expiration for a stock, with prices and stats. It looks overwhelming. You only need to read six columns, and you only ever look at a small slice of it.

The columns that matter

• Bid / Ask. What buyers will pay and what sellers want. The spread between them is your immediate cost. A $1.00 bid and $1.20 ask is a 20-cent spread: you're down 17% the moment you buy at the ask. On liquid options the spread is a penny or two.
• Volume. Contracts traded today. High volume means you can get in and out easily.
• Open interest. Contracts that exist and are still open. High open interest means a deep market. Both volume and OI in the thousands is what you want.
• IV. Implied volatility for that strike. Compare it to the stock's usual level.
• Delta. Your probability-and-sensitivity number from the last lesson.

What liquid looks like

For day trading, stay on the biggest, most-traded stocks and index ETFs. Their weekly options have penny-wide spreads and enormous volume. A small-cap stock's options might have a 30-cent spread and 12 contracts of volume, which means you're paying a huge tax to enter and you may not be able to exit at all. Rule: if the spread is more than about 5% of the option's price, or volume is under a few hundred, it's not a day-trading contract.

Expirations

Most liquid stocks have options expiring every Friday, and the biggest ones expire every day. For day trading you'll use the nearest expiration or the one after it. Nearest is cheapest and most explosive (high gamma, brutal theta). One week out costs more but forgives a slow start. Same-day expiration (0DTE) is where beginners get destroyed: the option can lose 50% in an hour of sideways trading. Not in the first six months.

Day trading options is stock trading with a different vehicle. The setup comes from the stock chart: a breakout, a pullback, a VWAP reclaim, an opening range break. Everything from Foundations applies. The option is just how you express it, and choosing the wrong one turns a correct read on the stock into a losing trade.

The default contract

• Underlying: a large, liquid stock or index ETF with penny-wide option spreads. Not the meme stock of the day.
• Direction: calls for a long setup, puts for a short setup. No spreads, no selling, for now.
• Strike: slightly in the money or at the money, delta 0.50 to 0.65. Enough delta to actually move with the stock, not so deep that the contract costs a fortune.
• Expiration: this week's or next week's. Not today's.
• Size: the number of contracts where a full loss of the premium equals your normal risk, or where your planned stop on the option equals it. Covered in lesson 7.

Why slightly in the money

An in-the-money option has intrinsic value that doesn't decay. If the stock stalls, an ATM or OTM option bleeds theta all day; the ITM one holds its intrinsic value and only loses on the smaller extrinsic portion. You give up some percentage upside for a much more forgiving trade. As a beginner, forgiving wins.

Match the expiration to the trade

A scalp you'll hold for 20 minutes can use this week's expiration. A trade based on a daily-chart level that might take the whole session should use next week's, so theta doesn't eat you while you wait. If you're honestly not sure how long the trade takes, go further out. The extra cost is insurance against being right too early.

Now the mechanics. An options day trade lives and dies on entries taken from the stock chart, exits decided in advance, and a refusal to hold a decaying asset while hoping.

Entry

1. Wait for the stock setup to trigger on the stock chart. Never enter because the option "looks cheap" or "is moving."
2. Use a limit order at or one cent above the ask on liquid options. Never a market order on an option. Ever.
3. Note the stock price at entry. Your stop is on the stock, not on the option's price. If the stock breaks the level that invalidates the setup, you're out regardless of what the option is doing.

Exits: three of them, all decided beforehand

• Stock stop. The stock price where the setup failed. When it hits, sell the option at the bid. Do not wait for the option to "come back."
• Profit target. The stock level from your plan, or a percentage on the option. Many traders sell half at +30% to +50% on the contract and trail the rest.
• Time stop. If the stock hasn't moved within 15 to 30 minutes, the trade is dead and theta is charging rent. Get out flat or small-red and look for the next one.

Scaling out

Because option gains come fast and reverse fast, most experienced day traders sell in pieces. Half at the first target, a quarter at the next, the last quarter on a trailing stock stop. It guarantees a win on the position early and lets the runner run without your whole P/L riding on the last tick.

The Foundations risk rules still apply. Options add three new ways to get hurt, so they get three extra rules.

Size by premium, assume it can go to zero

The simplest, safest way to size: the total premium you pay is at or under your risk per trade. With a $5,000 account and 1% risk, that's $50, which might mean one cheap contract or nothing at all. That sounds restrictive. It is. Options traders who blow up are almost all sized as if the option can't go to zero. It can, in an hour.

A slightly more aggressive version: size so that your planned exit on the option (say, a 40% loss when the stock stop hits) equals your risk. $50 risk with a 40% stop means $125 of premium. Only use this once you have proven you actually take the stop.

The three options-specific rules

1. No overnight holds on day trades. Theta, gap risk, and IV changes all work against you while you sleep. If it didn't work today, it's closed today.
2. No trades through known events. Earnings, major economic reports, product launches. IV crush after the event can make a correct directional call lose money.
3. Daily max loss counts premium. Three full losses at 1% each is your 3% daily limit. Done for the day, screen off.

The PDT rule still applies

Options day trades count toward the pattern day trader limit exactly like stock day trades. Under $25,000 in a margin account, you get three round trips in five business days. Plan for it: two or three high-quality setups a week, not ten scalps a day.

A stock replays a trading day in 5-minute candles with VWAP and the opening range marked. You choose calls or puts, a strike, and this week or next week's expiration. Options are priced live from the stock, time and volatility, and the clock ticks toward expiration as the day goes on. $5,000 account. Graded on the rules.

After this path

Paper trade options for at least two months using only the default contract from lesson 5. Journal the stock price at entry and exit next to the option price. When you can tell whether your losses come from bad reads or bad contracts, you're ready for small real size. Then the options swing path, where the same instrument meets slower setups.