Member tool
Put Diagonal Visualizer
Buy time with a longer-dated put, fund it by selling a shorter-dated put below. The short expiry is the decision point — see exactly where you stand when it arrives.
Your trade
Type in the numbers from your broker screen. Everything updates as you type.
What the stock is trading at right now.
Enter a stock price above zero.
Long put — the one you buy
Enter a strike above zero and above the short strike.
The longer date — months out.
Enter more days than the short expiry.
Short put — the one you sell
Enter a strike above zero and below the long strike.
The nearer date — this is the decision point.
Enter zero or more days, fewer than the long expiry.
What you pay for the pair, per share — the long put's ask minus the short put's bid (×100).
Enter a debit above zero.
Your guess at volatility when the short put expires — 30 is a calm large-cap; higher if the stock swings. This prices the long put's leftover value.
Enter a volatility above zero.
Profit / loss at the short expiry
Per spread — the long put is re-priced with its remaining days, using the volatility you entered.
How the math worksEvery formula, in one line each
Put Diagonal Visualizer: questions
Straight answers about the trade this tool maps.
What is a put diagonal spread?
You buy a longer-dated put and sell a shorter-dated put at a lower strike against it. The short put's faster time decay helps pay for the long put. Our rolling put diagonal guide shows the version run on micro futures.
Why does the tool measure P&L at the short expiry?
The short expiry is the decision point. At that date the short put is worth exactly its intrinsic value, while the long put still has time left, so the tool re-prices it with the volatility you enter. The result is where you stand when you must close, roll or let it go.
Where does a put diagonal make the most money?
Near the short strike at the short expiry. There the short put expires worthless while the long put keeps the most value. Far above, the long put melts toward zero and the debit is lost; far below, the long put's extra strike width cushions the fall.
What is the max loss on a put diagonal?
The tool shows the worse of two cases: a hard rally, which loses the full debit you paid, and a total crash, where the long put's extra strike width offsets the short put. The long put's value is an estimate, so a volatility collapse can shrink it.
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