A standard butterfly that has had the further OTM wing pulled (cut and pasted) further away from ATM than the natural sequential order of strikes dictates. A typical butterfly with a stock at $100 may look as follows: Buy one 100 call, Sell two 105 calls, Buy one 110 call. A broken wing may look as follows: Buy one 100 call, Sell two 105 calls, Buy one 120 call. BWB is an abbreviation for broken wing butterfly.