Payoff at expiryYour figures
Max gain
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Max loss
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Breakeven
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Net premium
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The position
Set this to the contract's real lot size.
How to read it
A flat section means the outcome has stopped changing — that is where a loss or a gain is capped. A section that keeps sloping to the edge of the chart is not capped, and "Unlimited" appears above.
The dot on the zero line is breakeven. Spreads often have one; positions with legs on both sides can have two. Anything between them is a loss, however small.
What this leaves out
Expiry only — it says nothing about what the position is worth before expiry, where time value and implied volatility still matter. Brokerage, STT, exchange charges and slippage are excluded, and margin requirements for sold options can be far larger than the premium received.