Strike Price and Expiry
Understand how strike price and time to expiry shape crypto option moneyness, premium, exercise value, liquidity and event risk.
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Strike and expiry define the option’s economic boundary in price and time. They cannot be evaluated independently: a strike that looks close today can become far away after a large crypto move, while an expiry that seems distant can lose optionality rapidly as time runs down.
Strike price and moneyness
The strike is the contractual reference level used to determine exercise/settlement value. Moneyness describes the relationship between spot/reference price and strike:
| Option | In the money | At the money | Out of the money |
|---|---|---|---|
| Call | Spot above strike | Spot near strike | Spot below strike |
| Put | Spot below strike | Spot near strike | Spot above strike |
Moneyness is not profitability. A buyer may need substantially more intrinsic value than zero to recover premium.
Expiry is a rule set, not just a date
Expiry specifies when optionality ends and final settlement is determined. Read the contract for:
- exact expiry timestamp and timezone;
- exercise style and whether exercise is automatic;
- final settlement index or fixing window;
- contract multiplier and settlement currency;
- trading cut-off before settlement;
- handling of exceptional index or venue disruptions.
How strike and expiry interact
| Choice | Typical premium effect, all else equal | Economic trade-off |
|---|---|---|
| Call strike closer/lower | Higher | More intrinsic/moneyness value |
| Call strike farther/higher | Lower | Requires larger move for intrinsic value |
| Longer expiry | Higher | More time for a move, more volatility exposure |
| Shorter expiry | Lower | Less time; more event-timing sensitivity |
These are directional relationships, not quotes. Implied volatility, skew, rates and liquidity can alter observed premiums.
Worked comparison
Spot is £80,000. Consider three hypothetical one-month calls:
- £75,000 strike: premium £8,000
- £80,000 strike: premium £5,000
- £90,000 strike: premium £1,800
If expiry spot is £88,000, the £75,000 call has £13,000 intrinsic value and simplified P&L +£5,000; the £80,000 call has £8,000 intrinsic and +£3,000; the £90,000 call expires with no intrinsic value and loses £1,800. The cheapest option was not automatically the best expression of an £8,000 rise.
Changing the expiry would change all three premiums and their sensitivity to time/volatility.
Common mistakes and misunderstandings
- Choosing a strike solely because it matches a price target.
- Assuming farther out-of-the-money options are “cheap” without considering probability and volatility.
- Ignoring the exact UTC expiry/fixing time.
- Comparing premiums across expiries as if time exposure were identical.
- Treating moneyness as a statement of profit or expected return.
Knowledge checkpoint
Q1. Why is an out-of-the-money option not necessarily mispriced because its premium is small?
Q2. Which expiry fields must be verified beyond the calendar date?
Q3. Why can two calls with the same strike but different expiries have very different premiums?
Q4. Why is moneyness different from trade profitability?
FAQ
❓ What does “at the money” mean?
It generally means the underlying/reference price is near the strike, but exact conventions can differ by analytics system.
❓ Does a farther strike always mean a better risk/reward?
No. Lower premium comes with a lower probability of finishing with intrinsic value and different Greeks.
❓ Do crypto options expire at midnight?
Not necessarily. Each venue defines an exact expiry and settlement methodology.
❓ Can I compare options using premium alone?
No. Strike, expiry, multiplier, volatility, liquidity and settlement must be normalised.
Summary
- Strike defines the contractual price boundary; expiry defines the time boundary.
- Moneyness does not equal profitability because premium matters.
- Strike and expiry jointly determine premium and Greeks.
- Exact settlement timing and reference methodology are operationally important in crypto options.
Use this lesson as one component of a wider risk and execution process. Derivative specifications, margin formulas, settlement and loss-allocation rules can differ substantially between venues.
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