What is an Iron Butterfly?
An Iron Butterfly uses four options with the same expiration.
Limits downside risk.
Collects premium.
Collects premium at the same strike as the short put.
Limits upside risk.
Core structure
The short put and short call share the same strike. That middle strike is the price where maximum profit occurs at expiration.
| Leg | Action | Strike | Purpose |
|---|---|---|---|
| 1 | Buy to Open Put | Lower strike | Downside protection |
| 2 | Sell to Open Put | Middle strike | Collect premium |
| 3 | Sell to Open Call | Same middle strike | Collect premium |
| 4 | Buy to Open Call | Higher strike | Upside protection |
When to use it
| Situation | Fit? | Why |
|---|---|---|
| Expect stock near one specific target | Good fit | Maximum profit occurs at the middle strike. |
| Expect low or falling volatility | Potentially favorable | The strategy benefits when option premiums decay and price stays contained. |
| Want premium income with defined risk | Good fit | The long wings cap both upside and downside risk. |
| Expect a large move | Poor fit | Profit declines quickly as the stock moves away from the middle strike. |
| Do not have a target price | Harder to use | The strategy is highly sensitive to where the stock finishes. |
Worked example
Assume a stock trades near $100 and you expect it to finish close to $100 at expiration.
| Leg | Action | Strike | Example Premium |
|---|---|---|---|
| 1 | Buy $95 Put | $95 | Pay $1.00 = -$100 |
| 2 | Sell $100 Put | $100 | Receive $3.00 = +$300 |
| 3 | Sell $100 Call | $100 | Receive $3.50 = +$350 |
| 4 | Buy $105 Call | $105 | Pay $1.50 = -$150 |
Maximum profit, maximum loss, and break-even
Maximum profit occurs if the stock finishes exactly at the middle strike: $100.
What happens at expiration?
| Stock Price | Approximate Outcome | Meaning |
|---|---|---|
| $90 | -$100 max loss | The lower put wing caps further downside loss. |
| $95 | Near max loss | The put spread reaches its full width. |
| $96 | Lower break-even | Loss on the put side offsets the $4 credit. |
| $98 | Partial profit | The position is still inside the profitable range. |
| $100 | +$400 max profit | Ideal expiration point. |
| $102 | Partial profit | The call side has some intrinsic value, but credit still exceeds it. |
| $104 | Upper break-even | Call-side loss offsets the credit. |
| $105 or higher | -$100 max loss | The long call wing caps further upside-side loss. |
Why the Iron Butterfly can offer a large credit
The short put and short call are both sold at the same middle strike, usually near the current stock price. Those options tend to contain relatively high time value.
Iron Butterfly vs. Iron Condor
| Feature | Iron Butterfly | Iron Condor |
|---|---|---|
| Short strikes | Same middle strike | Separate put and call strikes |
| Profit zone | Narrower | Wider |
| Typical credit | Higher | Lower |
| Maximum profit | At one middle strike | Anywhere between the two short strikes |
| Best use | Very specific target price | Broader range-bound view |
| Risk | Defined | Defined |
Iron Butterfly vs. Long Call Butterfly
| Feature | Iron Butterfly | Long Call Butterfly |
|---|---|---|
| Opening cash flow | Credit received | Debit paid |
| Middle-strike view | Same | Same |
| Maximum profit | At middle strike | At middle strike |
| Risk | Defined | Defined |
| Structure | Calls + puts | Calls only |
How to choose strikes
| Choice | Typical Effect |
|---|---|
| Middle strike at expected target | Centers maximum profit at your forecast price. |
| Narrower wings | Lower max loss, but less room and often different credit profile. |
| Wider wings | Can increase risk and buying-power requirement. |
Time decay and volatility
Often helps if the stock stays near the middle strike because the short options lose time value.
Falling volatility can help after entry; rising volatility can make the position more expensive to close.
Assignment risk
The short put and short call can both be assigned before expiration if they become in the money. Because the position includes protective wings, theoretical risk is limited, but operational handling can still become complicated.
Pros and cons
- Receive a relatively large credit upfront.
- Defined maximum loss.
- Time decay can work in your favor.
- Can offer attractive reward relative to risk in some setups.
- Useful when you have a strong target-price view.
- Narrow profit zone.
- Requires accurate price and timing forecast.
- Large moves in either direction hurt.
- Four legs increase complexity.
- Assignment risk exists on both short options.
How to close it
An Iron Butterfly is usually opened for a credit and closed for a debit.
Close: buy back the full Iron Butterfly for a net debit.
Example: open for $4.00 and later close for $1.50.
Common mistakes
- Using an Iron Butterfly without a realistic target price.
- Focusing only on the large credit and ignoring the narrow profit zone.
- Entering before a major event that could cause a large price move.
- Ignoring bid/ask spreads across all four legs.
- Holding into expiration without understanding assignment risk.
- Assuming any range-bound stock is suitable; the range must be tight enough around the middle strike.
Beginner checklist
| Check | Question |
|---|---|
| ☐ Target price | What price do I realistically expect at expiration? |
| ☐ Middle strike | Is the short call/put strike close to that target? |
| ☐ Wing width | What is my exact maximum loss? |
| ☐ Net credit | Is the credit attractive relative to the risk? |
| ☐ Break-evens | How narrow is my profitable range? |
| ☐ Volatility | Could volatility expand and hurt the position? |
| ☐ Events | Are earnings or major catalysts inside the expiration window? |
| ☐ Exit plan | Will I close early if the stock moves away from the middle strike? |
Key takeaway
Use it when you expect the stock to finish very close to one target price and want to collect premium with defined risk.
The main trade-off is: larger credit than an Iron Condor, but a much narrower profit zone.