Iron Butterfly
An iron butterfly sells an at-the-money call and put and buys wings for protection, profiting when a stock stays still. Learn how this defined-risk income trade works.
An iron butterfly is a four-leg options trade that profits when a stock stays still. You sell a call and a put at the same middle strike to collect premium, then buy a call and a put further out as protection. It is the opposite of a straddle: instead of betting on a big move, you bet on no move at all.
It sounds complex with four legs, but the idea is simple once you see the shape. Let me build it up.
Betting on Boredom
Most beginners bet on a stock going up or down. An iron butterfly bets on a stock going nowhere. If you think a stock will hover right where it is until expiration, this trade pays you for that stillness.
Here is how it is built, in two pairs. The inner pair is a sold straddle: you sell a call and a put at the same middle strike, collecting a fat premium. That is where your income comes from. The outer pair is a bought call and put further out, the "wings," which cap your risk if the stock moves against you. Selling the middle and buying the wings is what makes it defined-risk.
Watch It Work
Apple is at $200 and you think it will stay right around there. You build the iron butterfly:
- Sell the $200 call and sell the $200 put (the middle), collecting a big premium
- Buy the $210 call and buy the $190 put (the wings), for protection
- Net credit collected: say $600
Apple sits at $200 at expiration. This is the bullseye. The sold call and put expire worthless, and so do your wings. You keep the entire $600 credit. Perfect stillness pays the most.
Apple drifts to $205. The $200 call you sold has some value working against you, but you still keep part of the credit. You profit as long as Apple stays within your break-evens (roughly $194 to $206 here, the middle strike plus or minus the credit).
Apple jumps to $215. Now it has moved past your wing. You take a loss, but the $210 call you bought caps it. Your max loss is the distance to the wing minus the credit, known before you ever entered.
When to Use It
An iron butterfly fits when you expect a stock to be calm and range-bound, with low or falling volatility. It profits most from stillness and from time decay, since the options you sold melt in your favor.
The trade-off is a narrow profit zone. Because you sold at the money, the stock has to stay in a fairly tight band. A related trade, the iron condor, widens that zone by selling out-of-the-money strikes instead, trading a smaller credit for more room. But the iron butterfly's appeal is the fat premium you collect for betting on boredom, with your risk capped by the wings.
- An iron butterfly sells an at-the-money call and put and buys wings for protection.
- It profits when the stock stays near the middle strike.
- Both max profit (the credit) and max loss are defined up front.
- It is the opposite of a straddle: it bets on no move.
Pop Quiz
Three quick questions to see what stuck. Pick an answer and the explanation shows up right away.
What does an iron butterfly bet on?
It profits from stillness. The closer the stock stays to the middle strike, the more of the credit you keep.
What do the bought "wings" do?
The outer bought call and put define your max loss, turning a risky sold straddle into a defined-risk trade.
When does an iron butterfly reach its max profit?
A bullseye at the middle strike lets all the sold options expire worthless, so you keep the full credit.
Bottom Line
An iron butterfly pays you to bet a stock stays put. You sell a call and a put at the middle strike for a fat premium, and buy wings further out to cap your risk. Perfect stillness at the middle strike is the bullseye that keeps the whole credit.
It is a defined-risk income trade for calm, range-bound markets, the mirror image of a straddle. Where a straddle needs a big move, the iron butterfly needs none at all.
Keep going: the sold core is a straddle, and the wings are built from a call and a put.