counterparty
(FINANCE) for a financial instrument, the person/institution who takes the opposite position. For example, in a credit default swap (CDS), the buyer is someone who needs insurance against the possibility that a borrower will default on a loan. In that case, the counterparty is whoever receives the CDS premiums, and pays out in the event of default.
The purpose of financial options is to minimize risk to the buyer; therefore, it creates potentially lucrative opportunities for the counterparty, because the counterparty takes on so much risk.
counterparty
n. a party thrown in response to another party in which the thrower of sed counterparty was not invited to the original party to diminish the total number of people that show up to the original party and make sed original party look lame
DUDE, let's throw a counterparty to make Davis's party look lame, by inviting everyone invited to his party and others so our party is bigger and better than his.