Butterfly Spread Options Strategy
A butterfly spread is a defined-risk options strategy designed to profit if the underlying finishes near a target price at expiration. This page calculates a long call butterfly: buy 1 call at K1, sell 2 calls at K2, and buy 1 call at K3, with K1 < K2 < K3 (typically evenly spaced).
How a Long Call Butterfly Works
The strategy is usually entered for a net debit. It has a limited max loss (the debit paid) and a limited max profit that peaks if the underlying closes at the middle strike K2 at expiration.
Breakevens (Typical)
For an evenly structured butterfly, breakevens are often around: Lower BE = K1 + Net Debit and Upper BE = K3 − Net Debit. Your exact breakevens depend on the premiums you enter.
Notes
This calculator shows expiration payoff. Real P&L before expiration depends on implied volatility, time decay, and bid/ask spreads.