First, the key terms.

Strike
The price specified for the option’s underlying transaction.
Premium
The amount paid for the option right.
Payoff
The contract’s outcome before subtracting all acquisition costs.

The idea, explained

A call concerns buying; a put concerns selling. At expiry, a simple call’s payoff per unit is max(S − K, 0), where S is the underlying price and K the strike. Profit also subtracts the premium and costs. Contract size, exercise style and settlement matter. Sellers take on obligations, with risks that differ sharply across strategies.

STEP 1

Identify the right

A call concerns buying the underlying; a put concerns selling it. Buyers pay for a right, while sellers take obligations. Exercise style, settlement and contract size affect what actually happens. Do not assume every contract has the same multiplier.

STEP 2

Subtract the cost

A call with positive expiry payoff can still lose money after the premium. A simple expiry break-even calculation ignores other costs and does not describe the option’s changing market price before expiry.

Follow a worked example.

For an illustrative call with strike $100 and premium $5 per unit, an expiry price of $103 produces $3 payoff but a $2 loss before costs. A positive payoff does not necessarily mean a profitable trade.

Walk it through, one step at a time

  1. A fictional call has strike $50 and premium $4 per unit. At expiry the underlying is $52.
  2. Call payoff is max($52 − $50, 0) = $2. Buyer profit before other costs is $2 − $4 = −$2 per unit.
  3. If the contract covers 100 units, that simplified loss is $200. Verify the actual multiplier and settlement terms.

Where people get stuck

Leverage magnifies exposure. An option buyer can lose the entire premium; some uncovered selling strategies can create far greater losses.

Now try it yourself.

Pause before opening each answer. Explain your reasoning in your own words.

1. Check the core idea

Why is a call with a $3 expiry payoff not profitable when its premium was $5?

Reveal the answer & reasoning

The premium is part of the cost. The net result is $3 − $5 = −$2 per unit before other costs.

2. Apply what you learned

What is the simplified expiry break-even underlying price for that call?

Reveal the answer & reasoning

$54, because the $4 payoff then offsets the $4 premium per unit. Transaction costs would raise the required amount, and this is not a promise of attainable profit.