February 16th, 2009, 3:10 pm
You pay someone money up-front or over time in order to earn the difference between some spot interest rate and a strike rate, whether that difference is positive or negative. I can't think of a natural use for this, it would probably be a speculative bet that interest rates will move a lot in one direction or the other, in other words, that the market has underestimated interest rate volatility.