When you buy an options contract, the price you pay is the premium. It is quoted per share, but each contract covers 100 shares, so a premium of $3.50 means you are paying $350 for one contract. That money goes to whoever sold you the option. If the trade does not work out, you don't get it back. The premium is your maximum loss as a buyer and your maximum gain as a seller.
Simple enough so far. Where it gets interesting is understanding why that premium is $3.50 and not $2.00 or $6.00, and why it might be $3.50 on Monday and $2.80 on Wednesday even though the stock barely moved.
The two pieces inside every premium
Every options premium is made up of two components: intrinsic value and time value (sometimes called extrinsic value). Understanding this split is probably the single most useful thing you can learn about options pricing.
Intrinsic value is whatever the option would be worth if you exercised it right now. A $50 call with the stock at $54 has $4 of intrinsic value. A $50 put with the stock at $47 has $3 of intrinsic value. If the option is out of the money, intrinsic value is zero.
Time value is everything else. It is the portion of the premium that exists because the contract has time left before expiration. More time means more opportunity for the stock to move in a favorable direction, so more time equals more time value. This is the part that decays. Every day that passes, time value shrinks a little. On expiration day, time value is essentially zero, and the option is worth only its intrinsic value (if any).
Here is a real example. Stock is at $100. The $95 call (which is $5 in the money) is trading for $8. Of that $8, $5 is intrinsic value and $3 is time value. The $105 call (which is $5 out of the money) is trading for $2. That entire $2 is time value, because the intrinsic value is zero.
If you buy that $105 call, every dollar you spent is at risk of evaporating through time decay if the stock does not move above $105 before expiration.
What moves the premium: stock price
This is the most obvious driver. When the underlying stock moves, the option premium moves with it (usually). How much depends on delta.
If you own a call with a delta of 0.60, the option's price goes up roughly $0.60 for every $1 the stock rises. Stock goes from $50 to $51, your call goes from $4.00 to roughly $4.60. Stock drops from $50 to $49, your call drops to around $3.40. For puts, the relationship is inverted: stock goes down, put premium goes up.
But delta is not constant. It changes as the stock moves (that rate of change is gamma). So the $0.60 estimate is an approximation that works for small moves but gets less accurate for larger ones. A $5 stock move will not produce exactly $3.00 of option price change on a 0.60-delta call because delta itself shifts during that move.
The stock price effect is intuitive and what most beginners focus on. But it is only one of several forces acting on the premium at any given moment.
What moves the premium: time decay
Time decay, measured by theta, is the daily erosion of time value. Every day that passes, your option loses a little value even if nothing else changes. This is the cost of holding an option position over time.
The rate of decay is not constant. An option with 90 days left might lose $0.02 per day in time value. The same option with 10 days left might be losing $0.08 per day. With 2 days left, maybe $0.15 per day. The decay accelerates as expiration approaches.
This acceleration is one of the most misunderstood aspects of options. People buy a call with three weeks left, the stock moves sideways for two weeks, and they are confused about why the option lost 40% of its value despite the stock staying flat. That 40% was time value draining out. The stock did not move against them. Time did.
If you are buying options, theta is your enemy. Every day you hold, you are paying rent. If you are selling options, theta is your friend. Every day that passes puts money in your pocket, assuming the stock cooperates by not moving too far against you.
What moves the premium: implied volatility
This is the one that catches people off guard the most. Implied volatility (IV) is the market's estimate of how much the stock is likely to move before expiration. When IV is high, premiums are expensive. When IV is low, premiums are cheap.
Think of it this way. If a stock has been bouncing around wildly, swinging 3-4% per day, the options market prices in that movement. There is a higher chance the stock will reach an outlying strike price, so options at those strikes cost more. If the stock has been trading in a tight range for weeks, IV drops, and premiums get cheaper because the market does not expect big moves.
The tricky part is that IV can change independently of the stock price. The stock might not move at all, but IV could spike because of an upcoming earnings announcement, an FDA decision, or a geopolitical event. When that happens, option premiums increase even on a flat stock. And when that expected event passes (whether or not anything dramatic happens), IV tends to collapse. This is the famous "IV crush."
IV crush is particularly painful for option buyers around earnings. You buy a call before earnings because you think the stock will go up. The stock does go up, maybe 3%. But IV drops from 80% to 40% after the announcement, and the time value portion of your premium gets crushed. Your call might actually lose money even though the stock went in your direction. I have seen this confuse people more than almost anything else in options.
What moves the premium: interest rates and dividends
These two factors exist but have a much smaller effect on the premium than the three above.
Higher interest rates slightly increase call premiums and slightly decrease put premiums. The logic is that buying a call instead of buying the stock frees up capital that could earn interest. When rates are higher, that benefit is worth more, so calls are priced slightly higher. In practice, unless you are trading LEAPS (options with more than a year until expiration), interest rate effects on daily premium changes are negligible.
Dividends affect premiums because the stock price drops by the dividend amount on the ex-dividend date. Call premiums tend to be slightly lower on dividend-paying stocks (the expected price drop is priced in), and put premiums tend to be slightly higher. Again, this is a secondary effect for most traders.
Why the same option costs different amounts on different days
Take a $50 call with 30 days to expiration. On Monday, the stock is at $48, IV is at 35%, and the call is trading for $1.80. On Friday, the stock is still at $48, IV is still around 35%, but the call is now $1.50. What happened?
Four days of time decay. Nothing dramatic. But theta ate $0.30 out of the premium over those four days. The stock did not move. Volatility did not change. Time just passed.
Now take a different scenario. Same $50 call, same $48 stock. On Monday, IV is at 30% and the call is $1.40. On Wednesday, a news story drops about a potential takeover, IV spikes to 50%, and the call jumps to $3.20. The stock only went from $48 to $48.50. But the expectations about future movement changed dramatically, and the premium reflected that immediately.
Then the takeover rumor is denied on Thursday. IV drops back to 32%. The call falls to $1.60. You bought at $3.20 and it is now $1.60, even though the stock is actually $0.50 higher than when you entered.
This kind of thing happens all the time. If you only watch the stock price, you will constantly be confused by what your options are doing.
How to tell if you are overpaying
There is no perfect formula for this, but there are a few things to check.
Look at IV percentile or IV rank. These metrics tell you whether current IV is high or low compared to the stock's own history. If IV rank is at 90th percentile, it means current IV is higher than it was 90% of the time over the past year. Buying options at high IV means you are paying elevated premiums. That does not mean the trade is bad, but it does mean the bar is higher for you to make money.
Compare the premium to the expected move. If you are paying $5 for a $100 call and the stock would need to reach $105 just to break even, ask yourself: do I genuinely believe this stock is going to move 5% or more before expiration? If you are not confident in a move that large, the premium is probably too high for this trade.
Check the bid-ask spread. A wide spread means you are paying a premium over the theoretical fair value just to enter the trade. If the bid is $2.00 and the ask is $2.40, you are starting with $0.40 of slippage per share. That is $40 per contract that you are giving up before the trade even starts.
Premium behavior for buyers vs sellers
This is worth being explicit about because the incentives are completely opposite.
As a buyer, you want the premium to go up after you buy. You want the stock to move in your favor fast enough to outpace time decay. You want IV to stay stable or increase. Your worst day is a flat stock with declining IV to go with time passing.
As a seller, you want the premium to go down after you sell. You want the stock to stay still or move away from the strike you sold. You want time to pass (theta working for you) and IV to decrease (making the option you sold worth less). Your worst day is a big stock move toward your strike with IV spiking.
Most new traders are buyers because buying feels natural: you pay money, you hope it goes up, you sell for more. But selling options is a legitimate strategy where time decay and IV compression work in your favor instead of against you. The trade-off is that your maximum gain is the premium you collected, while your maximum loss can be much larger.
Premium and contract size: the multiplication most people forget
An option premium of $2.50 per share sounds manageable. But remember: one contract controls 100 shares. So you are actually paying $250. Ten contracts is $2,500. This is obvious when stated plainly, but I have watched people buy 10 contracts of a $4.00 option thinking they are risking a few hundred dollars, only to realize they just committed $4,000.
When the premium moves by $0.10, that is $10 per contract. A $0.50 swing is $50 per contract. If you are holding 20 contracts, a $0.50 premium move is a $1,000 change in your account. Premium movements feel small until you multiply by 100 and by the number of contracts. Then they feel very real.
Premium at expiration
At expiration, the premium converges to intrinsic value. Time value goes to zero. This means:
An in-the-money option's premium equals the intrinsic value. A $50 call with the stock at $53 is worth $3.00, period. No time value left.
An out-of-the-money option's premium is $0.00. The option is worthless. It expires and disappears.
An at-the-money option is worth somewhere close to zero, depending on which side of the strike the stock sits by the smallest margin.
This convergence to intrinsic value is the mechanism by which time decay ultimately resolves. All that time value you paid for when you bought the option? It is gone by expiration. The only question is whether the intrinsic value at that point exceeds what you originally paid.
What to read next
Premium pricing ties directly into the concepts of strike price and expiration date. The strike determines how much intrinsic value (if any) the premium contains, and the expiration determines how much time value remains.
If the concept of implied volatility grabbed your attention, we will cover it in depth in a future article on IV mechanics and how to read the VIX.
CallPutHub breaks down premium behavior through real market examples, showing exactly how intrinsic value and time value shift over the life of a contract. Watching these components change day by day through actual scenarios is the fastest way to build intuition for what you are paying and why.