a financial instrument used to part fools from their money. Usually involves speculating on interest rates. The fools, or 'mark', in this con are often unsophisticated public officials such as school boards or county commissions who are gambling with your money. The fools are advised by sleazeballs known as 'financial advisers' or 'consultants'. The sleazeballs are paid by both the fool and either directly or indirectly by the counterparty that makes a shitload of money, the greedy grifters often referred to as 'banks'. The banks only lose often enough to keep the hopeful fools signing up. By the time fools realize they have been had, it is a lose-lose situation. Pay enormous fees to terminate the contract, or continue riding it into the hole, hoping for a miracle.
Dude, why are your schools shit?

'Cause the board got fooled into a rate swap. We got jackshit and owe millions.
by Gaaaaaah! April 5, 2010
Get the Rate Swap mug.