A type of interest rate swap (IRS) in which the floating rate leg is derived from the difference between long and short-term interest rates. Curve steepeners used to be highly leveraged in their users’ quest to amplify returns, where the difference between long and short rates is usually augmented by a multiplier (10, 20, or even 50 times). An investor’s returns are positively proportionate to the difference between the two rates. Therefore, flat curves are not in the interest of steepener holders.