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Iron butterfly calculator
maximum credit, minimum room

An iron butterfly sells a straddle at the money and buys wings for protection. It collects far more credit than an iron condor because both short options are at the money — and for the same reason, the profitable range is much narrower. It is a condor with the shorts pushed together.

Outlook: Neutral — pinned near a price

Max profit
—
best case at expiry
Max loss
—
worst case at expiry
Breakeven
—
where the trade turns even
Net debit / credit
—
to open the position
Your iron butterfly
Per-share premiums. One contract = 100 shares.
100 shares per contract
Profit at expiry Loss at expiry Breakeven Strikes & spot

How a iron butterfly pays

Net credit = (short put + short call) − (long put + long call) Max profit = net credit × 100 × contracts (at the short strike exactly) Max loss = (wing width − net credit) × 100 × contracts Lower breakeven = short strike − net credit Upper breakeven = short strike + net credit
Worth naming. The credit is seductive and the range is unforgiving. An iron butterfly is a bet that the underlying finishes at one price, dressed up as an income trade. If you want room to be approximately right, an iron condor gives it at the cost of a smaller credit.

What this does not model

Every figure here is the payoff at expiry. Before then your position is marked at market prices that still carry time value, so a trade can show a loss while sitting exactly where you wanted it — falling implied volatility alone will do that.

Short legs carry assignment risk. American-style options can be exercised at any time, most commonly on in-the-money calls just before an ex-dividend date. The diagram assumes you hold every leg to expiry.

For the full version — Greeks, marks and what-if scenarios — that is what the GreeksView desk does, in your browser, against option-chain figures from our licensed market-data feed.

Frequently asked questions

What is the difference between an iron butterfly and an iron condor?
Where the short strikes sit. An iron condor separates them, creating a wide profit plateau and a smaller credit. An iron butterfly puts both at the same at-the-money strike, collecting far more premium but leaving only a narrow band around that single price where the trade wins.
What is the maximum profit on an iron butterfly?
The full net credit, and only if the underlying finishes exactly at the short strike so all four options expire worthless or offset. Anywhere else and you give back part of the credit.
Where are the breakevens?
The short strike plus and minus the net credit. Short at 100 with a $5.00 credit means breakevens at $95.00 and $105.00 — the position profits only inside that band.
How likely am I to be assigned?
Considerably more likely than on an iron condor, because your short options are at the money. An at-the-money option has roughly even odds of finishing in the money, so plan to close before expiry rather than letting the position settle.
Are commissions included in these numbers?
No — every figure is gross. On multi-leg positions this matters more than people expect: four legs to open and four to close is eight commissions against what may be a couple of hundred dollars of credit. Check your broker's per-contract rate against the max profit shown here before deciding a trade is worth putting on.

See it on a real chain

The numbers above are the ones you typed. Here is an iron butterfly built from SPY's own chain at the last close — real strikes, real premiums, with its breakevens and probability of profit.

SPY iron butterfly, priced from the close →

Run this on the GreeksView desk against a real option chain

GreeksView builds positions from real option chains, with Greeks labelled by source and delay, gamma exposure and what-if scenarios — in your browser, on figures from our licensed market-data feed.

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Educational tool only — not investment advice, and not a recommendation to enter any position. Options involve substantial risk and are not suitable for every investor. Figures are theoretical, exclude commissions and taxes, and assume the position is held to expiry. GreeksView is not a broker and does not hold funds.