Call and put directions reverse at the strike
Let S be spot and K the strike of an ordinary unadjusted option on that asset. The following classification uses S = $100. Whether the position is long or short does not change the contract classification. Moneyness also excludes the premium paid, so an ITM contract can still be a losing investment.
- Strict ATM means equality. When no listed strike equals spot, a chain may label the nearest strike or a range as near ATM. Record that rule instead of treating its label as exact equality.
- A ratio needs a named numerator: S/K above 1 is call ITM and put OTM; K/S reverses that sign. Here all forward ratios use F/K, and positive log(F/K) favors call moneyness.
- For an option on a futures contract, compare with the specified underlying futures month, not a cash index or a continuous futures chart. At expiration, the contractual settlement reference determines the final result.
| Strike K | Call at S = $100 | Put at S = $100 | Reason |
|---|---|---|---|
| $95 | ITM | OTM | S > K |
| $100 | ATM | ATM | S = K |
| $105 | OTM | ITM | S < K |