Construction: a put broken wing butterfly buys 1 OTM put, sells 2 further OTM puts, buys 1 even further OTM put — but the lower wing is wider than the upper wing (or vice versa), creating asymmetric risk. The asymmetry pays off in the form of a credit or near-zero cost entry. Profit zone exists between the long strikes; the wide-wing side has limited but defined loss; the narrow-wing side has minimal or no loss because of the credit collected.
Use case: high-probability income trade where you want defined risk and asymmetric reward. Often used as an alternative to short verticals when you want a wider profit zone with similar capital requirement. Common application: skip-strike butterflies on indexes for monthly income, sized to be no-loss on one side and small defined loss on the other.