Calculate intrinsic value first

For a call, intrinsic value is the positive amount by which the underlying exceeds the strike, otherwise zero. For a put, it is the positive amount by which the strike exceeds the underlying, otherwise zero.

In the hypothetical $105 stock and $100 call example, intrinsic value is $5 per share. If the option premium is $7, the remaining $2 is extrinsic value under that price observation. With a standard multiplier, the amounts scale by 100 per contract.

Keep the quote basis consistent

Use a clearly stated option price and a synchronized underlying observation. If the stock price is current but the option's last trade is stale, the arithmetic may appear strange for reasons unrelated to the concept.

Record whether you used bid, ask, midpoint, or a theoretical value. These conventions can produce different estimates of the remaining premium. A midpoint calculation is a description, not a guaranteed fill.

Understand what the remaining premium represents

Time remaining and implied volatility are among the factors that affect option value beyond immediate exercise value. The amount can change even when the stock moves very little. It should not be treated as a fixed surcharge that declines at one constant rate.

For a hypothetical out-of-the-money option, intrinsic value is zero while the option can still have a positive market premium before expiration. That premium can be lost if the contract ultimately expires without value.

Practice with four contracts

Create two call examples and two put examples, including both in-the-money and out-of-the-money cases. Calculate intrinsic value and the remainder using a specified premium. Check that you understand which inputs are observations and which are assumptions.

Then change only the underlying price in the example and recalculate intrinsic value. Notice that this does not by itself determine the full new option premium; the other pricing inputs still matter.

Tradex's structured lessons and simulated practice can help make these distinctions familiar. Explore the platform to connect the arithmetic with a broader understanding of options behavior and risk.