EdgeQuant TradingFoundations Series

Guide 02 of 02 · Options buying

Strike, Premium, Theta

Buying an option is buying a deadline. You are paying for the right to be correct about a price before a specific date — and the clock charges rent every day you hold. Thirteen panels on the buying side, and only the buying side.

This is education, not advice. No strategy, no signals, no view on any market. Options routinely expire worth nothing, and buyers can lose 100% of what they paid. Most people who buy options lose money over time. Speak to a licensed professional before risking capital.

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What you are buying, and what it costs to waitValue of one at-the-money contract

Illustrative shape, not a pricing model. Every price, ticker and figure in this guide is made up — none refers to a real instrument.

The contract

An option is a right with an expiry date

Buy an option and you have bought the right, but not the obligation, to trade a specific asset at a specific price until a specific date. You pay for that right up front. That payment — the premium — is the most you can lose, and it is gone the moment you spend it.

Four pieces define every contract. Any quote you see anywhere is just those values written in a row.

The multiplier catches people out constantly. The screen shows 3.40 and the account is debited $340. Ten contracts is $3,400 at risk, controlling 1,000 shares.

Anatomy of a quoteFive fields, one contract

One standard equity contract covers 100 shares, so a premium quoted per share is multiplied by 100 at the till.

Direction

Calls and puts

A call gains value as the underlying rises. A put gains value as it falls. Buying either is a bet on direction and magnitude and timing — all three have to work.

Note the break-even line. Buying a 110 call for 3.40 does not profit when the stock reaches 110. It profits above 113.40. The premium is a hurdle you clear before you make anything at all.

Strike is not break-even110 call bought for 3.40

Between the strike and break-even the option is worth something and you are still down money. That band is where most "but I was right" stories live.

	Long call	Long put
You want	Price up	Price down
Right to	Buy at the strike	Sell at the strike
Break-even at expiry	Strike + premium	Strike − premium
Max loss	The premium paid	The premium paid
Max gain	Theoretically unlimited	Capped — the underlying can only fall to zero

Shape

The payoff shape at expiry

These two shapes are the whole idea. The flat section is the premium you paid and cannot lose more than; the bend is the strike; the crossing point is break-even.

Before expiry the lines are curves rather than bends, because time value smooths the corner. As expiry approaches, the curve straightens into exactly this shape. That convergence is what time decay looks like on a chart.

Profit and loss at expiryLong call and long put

ProfitLoss

The flat floor is the defining feature of buying: whatever happens, the loss stops at the premium. Everything above the bend is what you paid that premium for.

Pricing

What the premium is made of

Every premium splits into two parts, and the split tells you what you are actually paying for.

Intrinsic value — what the contract would be worth if it expired right now. For a call: underlying minus strike, floored at zero. Real, and it cannot decay away.
Extrinsic value — everything else. The price of possibility. It decays to exactly zero at expiration, always.

Cheap out-of-the-money options feel appealing because the ticket price is small. The reason they are cheap is that the market has priced the probability of them paying off — and that probability is low.

Premium split by strikeCalls, underlying at 112

IntrinsicExtrinsic

Illustrative premiums. The far out-of-the-money strike on the right is entirely extrinsic — every cent of it is scheduled to disappear unless the underlying moves.

Term	Call	Put	Character
In the money	Stock above strike	Stock below strike	Has intrinsic value. Costs more, tracks the stock more closely.
At the money	Stock near the strike		All extrinsic. The most time value, and the fastest decay.
Out of the money	Stock below strike	Stock above strike	All extrinsic. Cheap, and most often expires worthless.

Time

Time decay works against you every single day

As a buyer you are on the wrong side of the clock. Each day that passes removes some extrinsic value from your contract even if the underlying does not move at all. That daily bleed is theta.

Decay is not linear. It is slow and gentle when expiry is months away, then accelerates sharply in the final weeks. This is why "I was right, just too early" is the most common sentence in options buying, and why it costs money rather than merely being annoying.

The practical consequence: a contract expiring in three days is almost pure decay, and one expiring in six months costs far more but gives your thesis room to be correct on its own schedule. Neither is free.

Extrinsic value as expiry approachesAt-the-money contract, price unchanged

Illustrative curve following the square-root-of-time shape that option pricing implies. The stock never moves in this chart — the entire decline is the clock.

Volatility

Implied volatility, and the crush

Implied volatility is the market's expectation of how much the underlying will move, backed out of the option's price. High IV means expensive options; low IV means cheap ones. It is the single largest driver of extrinsic value.

This creates a trap that surprises nearly every new buyer. Before a known event — earnings, a ruling, a trial result — IV rises, because a big move is plausible. You buy into that. The event happens, uncertainty resolves, IV collapses, and the option loses value even though the stock moved in your direction.

The lesson is not "never trade events." It is that direction alone does not determine your P/L. You can be right about what happens and still lose, because you paid for a level of uncertainty that no longer exists once the news is out.

IV crush around an eventSame contract, before and after

Worked illustration: the underlying closes 3% higher, which helps — and implied volatility falls from 68% to 34%, which hurts more. Net, the buyer loses on a correct call.

Sensitivities

The Greeks, from a buyer's chair

The Greeks are not a strategy. They are sensitivity measurements — how your contract's price responds to each input changing on its own.

Read together they describe the buyer's bargain plainly: gamma and vega can pay you, theta charges you daily, and delta decides whether the underlying's move was large enough to matter.

Delta across moneynessCall delta vs underlying price, strike 110

Deep out of the money the contract barely reacts to the stock; deep in the money it tracks it almost share-for-share. The steep middle is where gamma lives.

Greek	Measures	What it means when you're long
Delta	Change per $1 move in the underlying	Roughly how many shares your contract behaves like. A 0.40 delta call gains about $40 per contract on a $1 rise. Loosely read as rough odds of finishing in the money.
Gamma	How fast delta itself changes	In your favour as a buyer: gains accelerate, losses decelerate. Highest near the strike and near expiry.
Theta	Value lost per day	Always against you. Quoted per day per contract, and it grows as expiry closes in.
Vega	Change per 1 point of implied volatility	In your favour when IV rises, against you when it falls. The number IV crush acts on.
Rho	Change per 1% move in interest rates	Usually negligible for short-dated contracts. Matters for long-dated ones.

Arithmetic

Break-even and outcome at expiry

This computes the value of a long call or put at expiry only — no time value, no volatility, no early exit. It is the floor of the arithmetic, and the number worth checking before every purchase. Both the table and the chart redraw as you type.

Contract

Strike

Premium / share

Contracts

Shares / contract

Break-even at expiry—

Total cost / max loss—

Shares controlled—

Move needed from strike—

Price at expiry	Profit / loss

Your position at expiryLive

ProfitLoss

Drawn from the inputs above. The flat section is the total premium at risk; the dot marks break-even.

The asymmetry is the point: a wide band of outcomes returns exactly minus one hundred percent, and the profitable band starts past break-even rather than past the strike. Any honest expectation weighs how likely each row is, not just how good the best row looks.

Closing out

How the position actually ends

Four endings, and the first is by far the most common in practice. Buyers overwhelmingly sell the contract on rather than exercise it, because selling captures any time value that exercising throws away.

The ending that catches people is the one they did not choose: a contract left open into expiry gets handled by the broker, not by you.

How long option positions endIndicative distribution

Directional illustration of the well-known pattern that closing trades dominate and exercise is rare — not a measured statistic. Exact proportions vary by market, instrument and period.

Ending	What happens
Sell to close	You sell the contract to someone else before expiry, capturing whatever intrinsic and extrinsic value remains. Almost all buyers exit this way.
Expire worthless	The option finishes out of the money. It vanishes and you lose the entire premium. Nothing further is owed.
Exercise	You take the underlying at the strike. Rarely optimal before expiry — exercising throws away time value that selling would have captured.
Auto-exercise	Brokers typically exercise in-the-money contracts automatically at expiry. Without the cash or shares this can create a position you never intended. Close out beforehand rather than find out.

Mechanics

Details that cost real money

Spreads are wide. A contract quoted 3.30 bid / 3.60 ask costs 30 cents — nearly 9% — just to enter and leave. Use limit orders; a market order in an illiquid contract is a donation.
Check open interest and volume. A contract with a handful of trades a day may be impossible to exit at a fair price. Liquidity concentrates in near-dated, near-the-money strikes on heavily traded names.
Know your expiry style. American-style contracts can be exercised any time before expiry; European-style only at expiry. Index options often settle in cash rather than shares.

Corporate actions adjust contracts. Splits, special dividends and mergers change strikes and deliverables. An adjusted contract may no longer cover 100 shares.
Approval levels exist for a reason. Brokers gate options access by tier. Buying calls and puts sits at the lowest tier precisely because the loss is bounded at the premium.
Tax treatment differs by jurisdiction, holding period and instrument. Find out before, not at filing time.

What the spread costs you before anything movesRound trip on one contract, by quoted spread

On a 3.45 mid-price contract: the wider the quote, the further the underlying must move before you are level. Illiquid strikes routinely quote wider than the widest bar here.

Failure modes

Why option buyers lose

Buying options bounds your loss, which makes each individual loss survivable — and the accumulation of them easy to ignore.

Right direction, wrong window

The move happens the week after expiry. A stock position would have been fine; the option was worth zero. Buying too little time is the most common error there is.

Buying far out of the money because it's cheap

Low ticket price is not low risk — it is low probability, correctly priced. A string of small complete losses compounds downward exactly like large ones.

Paying up for volatility before an event

You buy the highest IV of the cycle, the event resolves, vega does its work, and the position loses even on a favourable move.

Sizing as if the premium were the risk budget

"Only $340 at risk" is true per contract and misleading in aggregate. Ten of them is $3,400 that can go to exactly zero at once, on a single correlated thesis.

Trading illiquid contracts

The gain shows on screen and evaporates in the spread. If you cannot exit at a fair price, the profit was never yours.

Holding into the last day hoping

Theta is at its most brutal and gamma cuts both ways. Hope is not a management technique; decide your exit before you enter.

Reference

Glossary

Premium: What you pay for the contract. Quoted per share, charged per contract.
Strike: The price at which the contract lets you transact.
Expiry: The date the right ends. Standard equity options expire monthly; many names also list weeklies.
Multiplier: Shares covered per contract — usually 100 for equities.
Intrinsic value: The contract's worth if it expired right now. Cannot decay.
Extrinsic value: Everything above intrinsic. Decays to zero at expiry.
Moneyness: Where the strike sits relative to the underlying: ITM, ATM, or OTM.
Implied volatility: Expected future movement, implied by the option's price.
Open interest: Contracts outstanding at that strike and expiry. A liquidity signal.
Assignment: Being required to fulfil a contract. A seller's concern, not a buyer's.
Exercise: Using your right to buy or sell at the strike.
LEAPS: Long-dated options, typically expiring more than a year out. Slower decay, higher premium.

One last time. This guide describes how option contracts work. It recommends nothing and forecasts nothing. Buying options is a bounded-loss instrument with an unbounded capacity to be used badly — the bounded part refers to a single contract, not to an account.

EdgeQuant Trading · Foundations series · Guide 02 of 02