How Option Premiums Work: Intrinsic Value, Time Value, and What Moves the Price

An option’s premium is the price the buyer pays and the writer receives, and it splits into two parts: intrinsic value, which is what the option would be worth if exercised immediately, and extrinsic value (also called time value), which is everything above that. Intrinsic value depends only on the stock price and the strike; extrinsic value depends on time left, expected volatility, interest rates, and dividends.

In short: premium = intrinsic value + extrinsic value. A call’s intrinsic value is the stock price minus the strike (if positive); a put’s is the strike minus the stock price (if positive). Extrinsic value is the price of possibility: it is largest for at-the-money options with lots of time and high expected volatility, and it shrinks to zero by expiration. Premiums are quoted per share, so a $2.60 premium costs $260 for a standard 100-share contract.

A common misconception

People new to options often think a cheap option is a “good deal” and an expensive one is “overpriced.” Price alone tells you very little. A $0.20 option may be cheap because it is very unlikely to pay anything, and a $6 option may be expensive because most of its price is intrinsic value that you’d have to pay for anyway. The useful question is not “how much does it cost?” but “how much of this is intrinsic, and what am I paying for the rest?”

Intrinsic value

Intrinsic value is the amount by which an option is in the money, and never less than zero:

Call: stock price minus strike, if the stock is above the strike. Otherwise zero.
Put: strike minus stock price, if the stock is below the strike. Otherwise zero.

With hypothetical Maple Widgets Inc. at $50:

Option	Intrinsic value per share
$45 call	$50 minus $45 = $5.00
$50 call	$0
$55 call	$0
$45 put	$0
$55 put	$55 minus $50 = $5.00

The terms “in the money” and “out of the money” describe exactly this; see in the money vs out of the money.

Extrinsic (time) value

Extrinsic value is the premium minus intrinsic value. It is what buyers pay for the chance that the option becomes more valuable before it expires, and what writers are compensated for carrying that risk.

Here are model prices for Maple options with about 60 days to expiration. They come from the Black-Scholes model with assumed 30% volatility, a 4% interest rate, and no dividends, rounded to the nearest $0.05 the way they might be quoted. They are illustrations, not market quotes.

Option	Premium	Intrinsic	Extrinsic	Contract cost
$45 call	$5.85	$5.00	$0.85	$585
$50 call	$2.60	$0	$2.60	$260
$55 call	$0.85	$0	$0.85	$85
$45 put	$0.55	$0	$0.55	$55
$50 put	$2.25	$0	$2.25	$225
$55 put	$5.50	$5.00	$0.50	$550

Notice that the at-the-money $50 options have the most extrinsic value. Deep in-the-money and far out-of-the-money options have less, because the outcome is closer to settled either way. (The $50 call costs a little more than the $50 put here because of interest rates; that relationship is called put-call parity and is covered in Black-Scholes explained.)

What moves the premium

Six inputs drive an option’s price before expiration. The direction of each effect, all else held equal:

Input rises	Call premium	Put premium
Stock price	Up	Down
Strike price (comparing contracts)	Lower	Higher
Time to expiration	Up	Up (usually)
Implied volatility	Up	Up
Interest rates	Up slightly	Down slightly
Expected dividends	Down slightly	Up slightly

The first two determine intrinsic value. The last four mostly affect extrinsic value.

Time

More time means more opportunity for the stock to move, so longer-dated options cost more. As expiration approaches, extrinsic value decays, and the decay is not even. Here is the model value of the Maple $50 call if the stock stays exactly at $50 and nothing else changes:

Days to expiration	Model call value	Contract value
90	$3.21	$321
60	$2.58	$258
30	$1.80	$180
14	$1.21	$121
7	$0.85	$85
1	$0.32	$32
0 (at expiry)	$0	$0

Going from 90 to 60 days costs about $0.63 per share. Going from 7 days to expiration costs $0.85, in a single week. Time decay speeds up near the end, which matters a great deal to anyone holding short-dated options. The measure of this is theta, explained in theta and time decay.

Volatility

An option’s price depends on how much the market expects the stock to move. The implied volatility (IV) is the volatility number that, when plugged into a pricing model, reproduces the market price. Higher IV means a higher premium for both calls and puts. The same 60-day Maple $50 call, at different volatility assumptions:

Implied volatility	Model call value	Model put value
20%	$1.78	$1.45
30%	$2.58	$2.26
45%	$3.79	$3.46
60%	$4.99	$4.66

Tripling the volatility assumption from 20% to 60% nearly triples the at-the-money premium. This is why options often get more expensive before known events, such as earnings announcements, and cheaper right after, when the uncertainty is resolved. That drop has a name, IV crush, and it is covered in implied volatility explained.

Interest rates and dividends

These effects are smaller for short-dated options but real:

Interest rates. Buying a call instead of the shares ties up less cash, which can earn interest; that makes calls slightly more valuable when rates are higher. Puts move the other way.
Dividends. On the ex-dividend date the stock price typically falls by about the dividend amount. Option holders don’t receive dividends, so an expected dividend lowers call values and raises put values.

Who sets the premium?

No one sets it. The premium is a market price, set by buyers and sellers on the exchanges, with market makers continuously quoting a bid (what they’ll pay) and an ask (what they’ll sell for). Pricing models such as Black-Scholes are tools that market participants use to judge whether a quote is reasonable given their volatility estimate; they are not the source of the price. How the quotes appear on screen is covered in how to read an options chain.

The same numbers from the buyer’s view

Breakevens follow directly from the premium:

Long call breakeven: strike + premium. For the $55 call at $0.85: $55.85.
Long put breakeven: strike minus premium. For the $45 put at $0.55: $44.45.

So the cheap $55 call needs Maple up nearly 12% in 60 days just to break even at expiration, and the $45 put needs it down about 11%. Low price and low odds tend to go together.

What can go wrong

Paying mostly for time. An option that is all extrinsic value loses that value steadily if the stock doesn’t move.
Buying high implied volatility. You can be right about direction and still lose money if volatility falls after you buy.
Reading a model price as a market price. Real quotes have bid-ask spreads, and illiquid options can trade well away from any model value.
Ignoring the multiplier. A $0.10 change in premium is $10 per contract; across 20 contracts, $200.

Common questions

Can an option trade for less than its intrinsic value?

For an American-style option, not by much and not for long, because anyone could buy it and exercise immediately to capture the difference. Small gaps do appear, especially in deep in-the-money options with wide bid-ask spreads, but the bid is the price you’d actually get. European-style options, which can’t be exercised early, can trade below intrinsic value in some cases, such as deep in-the-money puts when interest rates are high.

Why did my option lose value when nothing happened?

Because time passed. If the stock price and implied volatility both stay unchanged, an option’s extrinsic value shrinks every day toward zero at expiration. In the table above, the at-the-money call loses more than half its value between 30 days out and 7 days out with the stock unchanged.

Does a higher premium mean a better option?

No. A higher premium means the option is either worth more today (more intrinsic value), has more time left, or is priced with higher expected volatility. It says nothing about whether it will be profitable. A cheap option and an expensive one are just different bets on how far, and how fast, the stock moves.

Are premiums quoted the same way in Canada?

Yes. Montréal Exchange equity options are quoted per share in Canadian dollars, and a standard contract covers 100 shares, so a C$1.50 premium costs C$150 per contract. The same drivers (stock price, time, volatility, rates, and dividends) move Canadian premiums.

Is the premium the same as the cost of the trade?

The premium is most of it. You’ll also pay commissions and regulatory fees on each contract at most brokers, and the bid-ask spread is an indirect cost every time you buy at the ask or sell at the bid.

The takeaway

Every premium is intrinsic value plus extrinsic value. Intrinsic value is simple arithmetic between the stock price and the strike. Extrinsic value is the market’s price for uncertainty, driven mainly by time and implied volatility, and it always drains to zero by expiration. Knowing how much of a premium is each part tells you what you’re actually paying for.