Iron Butterfly Strategy: Higher Premium, Narrower Range
An iron butterfly sells a straddle and buys wings for protection. The exact payoff arithmetic, how it compares to an iron condor, and when the narrower range is worth the larger premium.
Arthalab10 min read
An iron butterfly sells a call and a put at the same at-the-money strike, and buys a call and a put further out as protection. It is a short straddle with capped risk — more premium than an iron condor, over a narrower profitable range.
The four legs
Leg
Action
Strike
Purpose
1
Sell 1 put (PE)
At the money
Collects premium
2
Sell 1 call (CE)
Same at-the-money strike
Collects premium
3
Buy 1 put (PE)
Below the sold strike
Caps the downside
4
Buy 1 call (CE)
Above the sold strike
Caps the upside
The two sold legs sit together at one strike — that is the body. The two bought legs sit either side — those are the wings. The structure is symmetric when the wings are equidistant.
The arithmetic
Let P be the net premium received and W the distance from the sold strike to either wing.
Quantity
Formula
Max profit
P, only if the index expires exactly at the sold strike
Max loss
W − P
Upside breakeven
Sold strike + P
Downside breakeven
Sold strike − P
Note the difference from a condor: maximum profit occurs at a single point, not across a range. That is the direct consequence of both sold legs sharing a strike.
Butterfly versus condor
Iron butterfly
Iron condor
Sold strikes
Both at the money, same strike
Two different out-of-the-money strikes
Premium collected
Larger
Smaller
Max profit
At one exact point
Across a range
Profitable range
Narrower
Wider
Win rate
Lower
Higher
Reward relative to risk
Better
Worse
Max loss
Capped at W − P
Capped at W − P
The trade is clean: a butterfly pays more and wins less often; a condor pays less and wins more often. Both cap the loss the same way. Which suits you depends on whether you would rather be right often for a little or occasionally for more.
What it is actually betting on
A butterfly is a sharper version of the same view a straddle expresses: that the index finishes close to where it is now, and that realised movement is smaller than priced.
It is more sensitive to that view being right. A condor tolerates a moderate move; a butterfly does not, because the profitable range is narrow and the sold strike is where the index already is.
Why it suits a sharper view
The flip side is that when the view is right, the butterfly pays considerably more for it. This is a structure for a specific and confident expectation rather than a general range-bound stance.
A worked example
Illustrative figures, chosen to show the arithmetic rather than to represent current prices.
The index is at 24,000. You sell the 24,000 call and the 24,000 put. You buy the 24,300 call and the 23,700 put, placing the wings 300 points either side.
Leg
Action
Premium
Sell 24,000 call
Received
+90
Sell 24,000 put
Received
+85
Buy 24,300 call
Paid
−42
Buy 23,700 put
Paid
−38
Net premium (P)
+95
With wings 300 points out and net premium of 95: maximum profit is 95 points, at 24,000 exactly. Maximum loss is 300 − 95 = 205 points. Breakevens are 24,095 and 23,905 — a 190-point band.
Against the condor
Compare that with the condor example: more premium (95 against 52) over a far narrower range (190 points against 600). That is the butterfly trade in one line.
The same assembly risk
Four legs, four orders, and the same failure mode as a condor. If the sold legs fill and the wings do not, you are holding a short straddle with uncapped risk on both sides.
On a butterfly this is slightly worse than on a condor, because the sold legs are at the money and therefore the most sensitive to a move. The straddle guide covers what you would be left holding.
Choosing the wings
The only real parameter is how far out the wings sit, and it is a direct trade between premium and worst case.
Wings further out. They cost less, so you keep more net premium. The maximum loss is larger because W is larger.
Wings closer in. They cost more, reducing net premium. The maximum loss is smaller.
Working backwards from the loss
There is no optimal answer. The sensible method is to pick the maximum loss you would accept in rupees, work back to the width that produces it, and then check whether the resulting premium makes the trade worth doing at all.
Automating it
1
Create four legs
Sell put and sell call at an at-the-money strike rule; buy put and buy call at a fixed offset either side.
2
Keep the wings symmetric
Equal distance either side keeps the maximum loss the same regardless of direction.
3
Set entry and exit times
An exit before the close removes overnight gap risk.
4
Set the square-off-all-legs rule
Without it, a partial fill leaves an uncapped position.
5
Set a strategy-wide max loss
This protects against the assembly case, which the structure itself does not cover.
All four legs and their strike rules are configured in the Option Strategy Builder without code.
The broken-wing variant
A common variation moves one wing further out than the other, which breaks the symmetry deliberately.
Placing the call wing further out than the put wing collects more premium — the further wing costs less — and raises the maximum loss on the upside while lowering it on the downside. The structure becomes directionally tilted.
When it is deliberate and when it is an accident
This is a legitimate adjustment when you have a mild directional view alongside the range-bound one. It is also a way to accidentally take directional risk you did not intend, if the wings end up asymmetric because of what happened to be liquid rather than because you chose it.
Why four legs cost more than you expect
Every leg pays brokerage, exchange charges and the bid-ask spread, on entry and again on exit. A four-leg structure therefore pays those eight times per round trip.
On a butterfly this bites harder than on a condor, because the sold legs are at the money where premiums are largest but the bought wings are further out where liquidity is thinner. You cross a wide spread precisely on the legs that exist to protect you.
What proportion of trades reached anywhere near the maximum profit?
How often did it hit the maximum loss?
What is the average win against the average loss?
Does the sample contain a period of larger moves, or only quiet conditions?
After costs on eight legs per round trip, is expectancy still positive?
The first question is the one specific to this structure. Because maximum profit is a single point, a report that looks attractive on theoretical maximums can be considerably less attractive on realised outcomes.
The short version
Sell both legs at the same at-the-money strike, buy wings either side
Max profit is the net premium, at one exact point only
Max loss is the wing distance minus the premium
More premium and a narrower range than an iron condor
A partially filled butterfly is a short straddle — set the square-off rule
If you want a wider profitable range and are willing to collect less, an iron condor is the same idea with the sold strikes separated.
Frequently asked questions
One where the wings are placed at different distances from the sold strike. It collects more premium and tilts the structure directionally, raising the maximum loss on one side and lowering it on the other.
Because maximum profit occurs only if the index expires exactly at the sold strike. Any distance from it reduces the result, so the headline figure is a ceiling rather than an expectation.
No, but if they are not, know which side carries the larger loss and confirm that is deliberate rather than an accident of which strikes happened to be liquid.
Brokerage, exchange charges and spread apply per leg on entry and exit — eight sets per round trip. Compute that total and subtract it from the net premium before judging whether the structure is worth running.
A butterfly sells both legs at the same at-the-money strike; a condor sells them at two different out-of-the-money strikes. The butterfly collects more premium over a narrower range.
The distance from the sold strike to the wing, minus the net premium received. It is capped by construction.
Because both sold legs share a strike. The full premium is retained only if the index expires exactly there, so realised profit is almost always below the theoretical maximum.
A butterfly pays more relative to what it risks, and wins less often. A condor wins more often for less. Neither is better; they suit different expectations.
Work backwards from the maximum loss you would accept. Wider wings keep more premium and raise the worst case; closer wings do the opposite.
You are holding a short straddle with uncapped risk on both sides, which is the precise thing the structure exists to prevent. Set the square-off-all-legs rule.
It is defined risk, which helps, but four legs means more execution cost and more ways for assembly to go wrong. A two-leg defined-risk spread is a simpler starting point.
Yes. Four legs with strike rules, entry and exit times, and the risk settings, all in the Option Strategy Builder.
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