Options Strategies

An option contract is a standardized agreement giving the buyer the right, not the obligation, to buy or sell 100 shares of an underlying asset at a fixed strike price before expiration. The exchange sets its terms (underlying, strike, expiry, size), so every contract on a given line trades as the same interchangeable product.

Full guide: Option Contract →

A call option gives its buyer the right to buy the underlying asset at the strike price before expiration. Traders buy calls when they expect the price to rise; the maximum loss is the premium paid, while the potential gain is theoretically unlimited as the underlying climbs.

A put option gives its buyer the right to sell the underlying asset at the strike price before expiration. Traders buy puts when they expect the price to fall, or to hedge shares they already own, much like insurance. Loss is capped at the premium paid.

The underlying asset is whatever an option's value is derived from: a stock, an ETF, an index, or a future. When the underlying moves, the option's price moves with it, often in a sharp, uneven way because of leverage and time decay.

Full guide: Underlying Asset →

The strike price (or exercise price) is the fixed price at which an option lets its holder buy (call) or sell (put) the underlying asset. It never changes during the contract's life; the stock price simply moves around it, which is what decides whether the option finishes in or out of the money.

The expiration date is the last day an option contract exists. Standard US equity options expire on the third Friday of the month, with weekly contracts expiring every Friday. After expiration the option is either exercised, if it has value, or it expires worthless.

The option premium is the market price of the contract, quoted per share. A $4.80 quote costs $480 for one standard 100-share contract. The buyer pays the premium up front; the seller collects it and keeps it no matter what happens to the position afterward.

Contract size is the number of shares one option contract controls. For US equity options that's 100 shares. Corporate actions like special dividends, splits, or mergers can produce oddly sized "adjusted" contracts, so it's worth checking the deliverable before trading an unusual one.

The multiplier is the number used to convert a quoted premium into its real dollar cost. For standard stock options it equals the contract size, 100 - a $0.87 quote costs $87. Index options like SPX also use a $100 multiplier, applied to the index level rather than to shares.

Moneyness describes where an option's strike sits relative to the underlying's current price - in-the-money, at-the-money, or out-of-the-money. It shows at a glance how much of the premium is real (intrinsic) value versus time (extrinsic) value, and it roughly tracks the option's delta.

An option is in-the-money (ITM) when exercising it right now would have value: the strike is below the stock price for a call, or above it for a put. ITM options already carry intrinsic value, cost more than OTM options, and move more closely with the underlying.

An option is at-the-money (ATM) when its strike sits at or very close to the underlying's current price. ATM options carry the most extrinsic (time) value of any strike, and that value also decays fastest, making them the most sensitive to the passage of time.

An option is out-of-the-money (OTM) when it has no intrinsic value: the strike is above the stock price for a call, or below it for a put. OTM options are cheap and made entirely of time value, so they expire worthless far more often than beginners expect.

Intrinsic value is what an option would be worth if exercised right now - the amount it's in-the-money by. It's calculated as max(0, stock price − strike) for a call or max(0, strike − stock price) for a put, and it can never fall below zero.

Extrinsic value (or time value) is the part of an option's premium above its intrinsic value - the price of the possibility that the stock still moves before expiration. It shrinks every day and hits zero at expiration, which is why holding a losing option can quietly cost money even when the stock barely moves.

A long position means you bought an option and hold the right to exercise it. You paid the premium up front, and that premium is your maximum possible loss; profit potential can be large, or unlimited for a long call, if the underlying moves your way.

A short position means you sold (wrote) an option you didn't already own. You collect the premium immediately but take on an obligation - to sell shares if a call is assigned, or buy them if a put is assigned - with risk that can exceed the premium received.

The bid-ask spread is the gap between the highest price a buyer will pay (bid) and the lowest a seller will accept (ask). It's a hidden trading cost: buying at the ask and selling right back at the bid loses the full spread, which matters most on thin, illiquid contracts.

Trading volume is the number of option contracts traded today; it resets to zero every morning. High volume signals active interest in a strike right now, and alongside open interest it's one of the two basic gauges of how liquid a contract is.

Open interest is the total number of option contracts still open - not yet closed, exercised, or expired. Unlike volume, it updates once per day and accumulates over time. High open interest at a strike usually means a crowd has positions there and spreads tend to be tighter.

Exercise is when an option holder uses their contractual right - buying the underlying at the strike for a call, or selling it for a put. US equity options are American-style, exercisable on any day before expiry, and brokers typically auto-exercise options that finish $0.01 or more in-the-money.

Assignment is what happens to the seller when a holder exercises: the clearing house (the OCC in the US) randomly selects a short position to fulfill the obligation. Sellers can't choose when it happens, and the risk rises sharply for deep in-the-money short calls right before ex-dividend dates.

Physical delivery means actual shares change hands when an option is exercised - exercising one $340 call moves $34,000 out of the buyer's account in exchange for 100 shares. All US single-stock and ETF options settle this way, which is why an auto-exercised option can leave an unplanned stock position.

Cash settlement means no shares change hands when an option is exercised - only the cash difference between the settlement price and the strike is paid. Broad index options like SPX and NDX settle this way, and they're also European-style, exercisable only at expiration.

The break-even price is where the underlying must be at expiration for a position to neither gain nor lose money. For a long call it's strike plus premium paid; for a long put it's strike minus premium paid, and every other strategy's break-even builds from those two ideas.

A derivative is a financial instrument whose value is derived entirely from something else and has no value of its own. Options, futures, and swaps are all derivatives - each is effectively a side bet tied to the price of an underlying stock, index, or other asset.

Full guide: Derivatives →

Liquidity is how easily a position can be entered and exited without moving the price against you. Check it with three things: a tight bid-ask spread, healthy open interest (ideally 1,000+ contracts at the strike), and steady daily volume rather than a single stray print.

Leverage means controlling a large amount of the underlying with a small amount of cash. One option contract can control tens of thousands of dollars of stock for a fraction of that price - amplifying gains and losses in both directions, and cutting losses faster than owning the stock outright would.

An American-style option can be exercised on any trading day up to and including expiration. Nearly all US single-stock and ETF options (AAPL, SPY, etc.) trade this way, which gives holders flexibility but exposes sellers to early-assignment risk at any point before expiry.

A European-style option can only be exercised on its expiration day, never before. Most cash-settled index options - SPX, NDX, RUT - use this style, which means sellers never face early assignment and holders can't lock in value ahead of the settlement date.

Automatic exercise (the OCC calls it "exercise by exception") means any option that finishes $0.01 or more in-the-money at expiration is exercised for you unless you tell your broker otherwise. It's convenient, but it can leave a trader holding an unplanned 100-share stock position on Monday morning.

Volatility measures how far and how fast an underlying's price swings, expressed as an annualized percentage. A stock with 25% volatility has a roughly ±25% expected range over a year. For option buyers, volatility is fuel for a bigger payoff; for sellers, it's the risk they're paid a premium to carry.

Historical volatility (HV) measures how much a stock actually moved over a past window, typically 20 or 30 trading days. Because it looks backward at realized price action, it's a measured fact rather than a forecast - useful for comparing against implied volatility to see if options look rich or cheap.

Implied volatility (IV) is the volatility figure built into an option's current market price - the market's forward-looking forecast of movement, derived backward from what traders are actually paying. High IV means expensive options; low IV means cheap ones, and it usually spikes ahead of known events like earnings.

The Greeks are a set of sensitivity measures - delta, gamma, theta, vega, and rho - that each show how an option's price reacts to one specific change: the stock moving, time passing, volatility shifting, or interest rates changing. Traders read them together, the way a pilot reads a full instrument panel.

Delta measures how much an option's price changes for a $1 move in the underlying. Calls range from 0 to +1 and puts from −1 to 0; it also works as a rough probability of finishing in-the-money, so a 0.20-delta option has roughly a 1-in-5 chance of doing so.

Gamma measures how much delta itself changes for a $1 move in the underlying - effectively delta's rate of acceleration. Gamma is highest for at-the-money options close to expiration, which is exactly when a small stock move can swing a position's risk the fastest.

Theta (time decay) measures how much value an option loses each day, all else held equal. It works against option buyers and for option sellers, and it accelerates sharply in the final two to three weeks before expiration, which is where long options bleed value the fastest.

Vega measures how much an option's price changes when implied volatility moves by one percentage point. Longer-dated options carry more vega than short-dated ones, which is why they're, above all, a bet on how volatility itself will move rather than just on the stock's direction.

Rho measures how much an option's price changes when interest rates move by one percentage point. Calls gain value as rates rise and puts lose value; it matters little for short-dated contracts but becomes more relevant on long-dated options such as LEAPS.

A covered short option is backed by an offsetting position - a covered call by 100 owned shares, a cash-secured put by cash to buy them. An uncovered (naked) short option has nothing behind it but margin, so a naked call carries theoretically unlimited loss since a stock has no price ceiling.

An opening transaction creates or adds to a position and increases open interest. Buying to open starts a long position; selling to open writes an option and starts a short position. It's the first leg of any new options trade.

A closing transaction exits an existing position and reduces open interest. Selling to close exits a long option; buying to close buys back an option that was previously written. Confusing a closing order with an opening one is a common and costly beginner mistake.

The VIX (CBOE Volatility Index) is the market's 30-day implied volatility for the S&P 500, calculated from SPX option prices, and it's often called the "fear gauge." A quick shortcut, the Rule of 16, divides the VIX by 16 to estimate the S&P 500's expected daily move.

The put-call ratio (PCR) divides put trading volume by call trading volume for a stock, index, or the whole market. A low ratio signals heavy call buying and optimism; a high ratio signals fear-driven put demand. Many traders read extremes as a contrarian sentiment signal rather than a forecast.

Early exercise is using an American-style option before its expiration date. It's rarely optimal, since exercising throws away any remaining extrinsic value - the main exception is a deep in-the-money call the day before an ex-dividend date, when the dividend exceeds the option's remaining time value.

Margin requirements are the collateral a broker holds against a short option position, since a short option can lose far more than the premium collected. US Reg T rules set a formula per position type, and the requirement is recalculated daily, growing if the trade moves against the seller.

Slippage is the gap between the price a trader expected and the price actually filled at, caused by wide spreads, thin order books, or fast-moving markets. It quietly erodes returns on illiquid contracts; using limit orders near the midpoint is the standard way to control it.

IV Rank shows where a stock's current implied volatility sits within its own 52-week high-low range, expressed as a percentage. It reacts quickly to a tight recent range but can be distorted by a single volatility spike that stretches the whole range.

IV Percentile shows the percentage of trading days over the past year when implied volatility was lower than it is today. Unlike IV Rank, a single outlier spike barely moves it, which is why many traders trust IV Percentile more in the year after a market crash.

Volatility skew is the difference in implied volatility across strikes within the same expiration. On stocks and indices, out-of-the-money puts almost always carry higher IV than out-of-the-money calls, because investors are willing to pay up for crash protection - a pattern traders call the "smirk."

A volatility smile is when implied volatility rises on both wings of an option chain - deep out-of-the-money puts and deep out-of-the-money calls - with the low point near the money. It shows up in FX options, meme stocks, and single names right before binary events like earnings.

Term structure of volatility compares implied volatility across different expirations at the same strike. Rising IV further out (contango) is typical in calm markets; near-term IV spiking above longer-dated IV (backwardation) usually signals a known event, like earnings, sitting inside that near-term window.

Skew risk is the risk that the shape of the volatility curve across strikes moves against a position even when at-the-money IV stays flat. It hits risk reversals and ratio spreads especially hard, since a crash can spike out-of-the-money put IV far more than the ATM IV a hedge relies on.

IV crush is the sharp drop in implied volatility right after a known event, usually earnings, once the uncertainty that inflated it is resolved. It can turn a directionally correct trade into a loss, since the volatility premium built into the option evaporates even as the stock moves the "right" way.

Realized volatility is the volatility a stock actually delivers over the life of a trade, measured from its daily price changes. Option selling as a business rests on implied volatility tending to run higher than realized volatility over time - sellers collect that gap as a premium, and give it back during sharp moves.

Put-call parity is the no-arbitrage relationship linking a European call and put with the same strike and expiration: their price difference equals the underlying's price minus the discounted strike. It explains why calls and puts share one implied volatility at a given strike and underpins synthetic stock positions.

Option pricing models turn stock price, strike, time, rates, dividends, and volatility into a theoretical premium. Black-Scholes is a fast closed-form formula for European options; the Binomial model checks for early exercise at each step, making it the standard choice for American-style stock options.

Rolling closes an existing option and opens a new one in the same order, shifting the strike, the expiration, or both. Rolling up moves to a higher strike, rolling down to a lower one, and rolling out to a later expiration - usually done to defend a losing position or buy more time.

Legging in means building a multi-leg spread one leg at a time instead of as a single combo order, and legging out closes the legs separately. It can capture a better net price if the underlying moves favorably between fills, but leaves a temporarily unhedged, fully directional position in between.

Assignment risk is the chance a short option gets exercised against you, forcing a trade at the strike. On American-style options it can happen any day, but it clusters around expiration, ex-dividend dates, and deep in-the-money contracts with almost no extrinsic value left to discourage the holder from exercising early.

Pin risk occurs when a stock closes right at or very near a short option's strike on expiration day, leaving uncertainty about whether it will be assigned. After-hours price moves can still trigger exercise decisions, turning a seemingly expired option into a surprise stock position over the weekend.

Dividend risk hits short call holders: if a call's remaining extrinsic value is smaller than an upcoming dividend, the holder tends to exercise early, the day before the ex-dividend date, to capture that dividend - leaving the option seller unexpectedly short stock and owing the payout.

Portfolio margin calculates collateral requirements from the actual risk of an entire account, stress-testing it across a range of price moves, instead of applying fixed Reg T percentages per position. It can free up significant capital for hedged positions but requires a larger minimum account and can jump sharply in a volatility spike.

Gamma scalping means holding long options (long gamma), hedging with the underlying stock, and re-hedging as the price moves to lock in small profits from each swing. Those scalping profits are what pay for theta, the daily cost of holding the long options - it only works if realized volatility beats the volatility paid for.

Max pain theory identifies the strike price at which the total value of all open options, calls and puts combined, is lowest at expiration - the price where option buyers as a group lose the most. Evidence for stocks actually drifting toward it is mixed, and the effect tends to vanish once real news hits.