According to the rules, each participating institute can make three bids max. These bids must stay within the determined bandwidth of exchange rates. The lowest bid is $100,000. Each bid must be a multiplication of $10,000. Just like before the FX auctions which are also known as forex auctions are aimed at stabilizing the prices of the American dollar. foreign exchange (FX) auction is a method used by central banks to buy or sell foreign currency, typically to manage the exchange rate and stabilize the domestic currency. In essence, it's a type of auction where the central bank determines the exchange rate by allowing banks to bid for or offer foreign currency at specified prices.