By Matt Connor · Why Some Options Cost So Much More
Two nearly identical options can carry wildly different prices. Implied volatility is why: the market's priced-in expected move, mapped across six names.
Two options can look almost identical. Same expiration, same distance from the money, the same 100 shares of stock underneath. One can still cost several times as much as the other. The difference is implied volatility: the market's priced-in estimate of how far the stock is likely to move before the option expires. A calm index fund and a jumpy single-name stock carry very different expected moves, and an option's price carries that gap directly.
Implied volatility is the market's expected move
Every listed option has an implied volatility attached to it. The exchange does not quote it. It is backed out of the option's own market price with a pricing model, and it reads as an annualized percentage: a rough measure of how much the market expects the stock to swing over the coming year. A higher number means the market is paying up for a bigger expected move. To see the range in one picture, here are six familiar names on July 6, 2026, each measured across its near-the-money contracts expiring July 17, sorted from calmest to wildest:
The exact SQL behind every number
SELECT underlying_symbol AS instrument,
round(avg(implied_volatility) * 100, 1) AS atm_iv_pct,
round(avg(underlying_close), 0) AS spot
FROM global_markets.options_greeks
WHERE date = '2026-07-06'
AND implied_volatility > 0.02
AND abs(strike_price / underlying_close - 1) < 0.05
AND (ticker LIKE 'O:SPY260717%' OR ticker LIKE 'O:QQQ260717%'
OR ticker LIKE 'O:KO260717%' OR ticker LIKE 'O:AAPL260717%'
OR ticker LIKE 'O:NVDA260717%' OR ticker LIKE 'O:TSLA260717%')
GROUP BY instrument
ORDER BY atm_iv_pctThe ladder runs from SPY at the bottom, 13%, to TSLA at the top, 47.6%. That is close to a fourfold spread on the same calendar week, on options that share an expiration date and a moneyness. SPY, a broad index fund, holds hundreds of stocks whose moves partly cancel, and it sits at the calm end. TSLA, a single stock that routinely travels on its own headlines, sits at the wild end. In between, KO at 20.2% and NVDA at 39.7% fill out the rungs. Read the number as a forecast the market is willing to back with real premium, not as a description of where the stock has already been.
Implied volatility is not a fixed trait of a name. It climbs ahead of known events like an earnings report and settles once the news is out. It rises across the whole market during a selloff, when every option gets more expensive at once, and it drifts lower through quiet stretches. The snapshot above freezes one ordinary Monday, well away from any of the six names' earnings dates. The ranking reads as the market's steady-state view of each name rather than an event spike.
The same option, a very different price
An option's premium moves with its implied volatility once the other inputs are held roughly equal. Take one near-the-money call option on each of the two extremes above, both expiring July 17, both priced on July 6. Each call controls the same 100 shares. Expressed as a share of the stock it sits on, the two premiums are worlds apart:
The SPY call cost $7.35 against a $751 share, about 0.98% of the stock. The TSLA call cost $16 against a $417 share, about 3.84%. Same structure, same eleven days to expiry, and several times the cost measured as a fraction of the underlying. The premium gap tracks the implied-volatility gap, not the identity of the ticker. A buyer of the TSLA call needs a far larger move just to break even, and the seller collects a far larger cushion for the same eleven days of risk.
Why the share price is not the answer
A natural guess is that pricier stocks make pricier options. The data cuts the other way. In the spectrum above, SPY trades near $751 a share and carries the lowest implied volatility of the six, while NVDA trades near $195 and carries one of the highest. The share price sets the strike spacing and the dollar size of one contract. It says nothing about the expected move. What an option charges for is uncertainty over the life of the contract, and implied volatility is how that uncertainty gets turned into a dollar premium.
The practical takeaway sits in the ranking itself. When one option looks expensive next to another, compare their implied volatilities before anything else. A high number tells you the market expects a big move and is charging accordingly. It marks an option priced for turbulence, not a mistake in the quote. A low number tells you the market expects calm. The option greeks all flow from the same input, and how the greeks change over time shows the premium re-pricing session by session as that expected move shifts.
FAQ
Why do two similar options have such different prices?
The answer is implied volatility, the market's priced-in estimate of the stock's expected move. Two options with the same expiration and moneyness on different stocks carry different premiums whenever the market expects one stock to move more than the other. The one on the more volatile name costs more.
What is implied volatility in one sentence?
It is the annualized move the market is currently pricing into an option, backed out of that option's market price with a pricing model. A higher reading means a bigger expected swing and a larger premium.
Does a higher stock price make an option more expensive?
No. The share price sets the dollar size of a contract and the spacing between strikes, not the premium as a share of the stock. In the snapshot above the highest-priced name carries the lowest implied volatility, and a lower-priced name carries one of the highest.
Is a high-implied-volatility option a bad buy?
Not on its own. A high reading means the market expects a large move and charges for it. The buyer then needs a bigger move to profit, and the seller collects a bigger premium. It describes the price of the expected move, never whether the trade works out.
How is implied volatility calculated?
A pricing model takes the option's market price, the stock price, the strike, the time to expiry, and the interest rate, then solves for the one volatility figure that reproduces the observed price. Our tape recomputes it for every listed contract each session.
Run this same spectrum for any set of tickers on the Strasmore terminal and watch where each name lands.