A basis point (often abbreviated as bp) is a unit of measurement that denotes a change in the interest rate of a financial instrument and is equal to 1/100th of 1% or 0.01%. It is a usual practice in the financial industry to use basis points to denote the difference (spread) between two interest rates.
See: In re State St. Bank & Trust Co. Fixed Income Funds Inv. Litig., 842 F. Supp. 2d 614 (N.Y. 2012)
[Last updated in May of 2022 by the Wex Definitions Team]