Range Accrual

A form of interest accrual in which the coupon rate is only earned on days when another rate from which the coupon is derived falls within a specified range. As such, there is no standard coupon rate that can be counted on for interest payments.

Investopedia Says:
Range accrual notes are complex instruments that are valued and adjusted in a similar manner to American style options. They are typically used by large institutions as a hedge of another position. No official market exists for range accrual notes trading or valuation.

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