The interest portion of mortgage, Treasury or bond payments, which is separated and sold individually from the principal portion of those same payments. The periodic payments of several bonds can be "stripped" to form synthetic zero-coupon bonds. Also, an IO strip might be part of a larger collateralized mortgage obligation (CMO), asset-backed security (ABS) or collateralized debt obligation (CDO) structure. 

|||Financial engineers, such as Wall Street dealers, frequently strip and restructure bond payments in an effort to earn arbitrage profits. Zero-coupon Treasury strips are an important building block in many financial calculations and bond valuations. For example, the zero coupon or spot-rate Treasury yield curve is used in option-adjusted spread (OAS) calculations and for other valuations of bonds with embedded options.