ISDA. International financial trade association that formulates and implements swap and derivative trading terms. The association is composed of a number of major derivative traders across 57 countries and has more than 850 members. ISDA was founded in 1985 and is based out of New York City. Since its conception, ISDA has published numerous agreements that have alleviated some of the market risks associated with private derivatives transactions. The association has created a contract known as the ISDA Master Agreement, which is used by the members when engaging in derivative transactions.