Originally Posted by Minnewaska
No, it's not. Just like trading stocks, any given price throughout the day will vary depending on how much you have to trade and the counterparty at the moment of the trade. Further, the traders themselves bid or ask to make a profit and must do so. Otherwise, there is no one out there to effect the exchange and take risk holding inventory.
Further, have you ever tried to exchange in the airport, at the hotel, in the restaurant. All widely different exchange rates.
All the financial institutions' agreements I've examined claim the exchange rate that is applied is set by the credit card company, not them. Most also insert some fudgy language saying the exact exchange rate that is applied is the one in effect when the purchase is debited to the user's account. This could be hours or even days out of sync of the actual purchase. However, that would still be easy to analyse. I'm not one to support banks, but I'd like to see actual proof of this allegation Minn.
This 2.5% off foreign currency purchases likely amounts to very small potatoes for most financial institutions. Most of their clients don't do this very often. I interpret this as some companies using this option as a low-cost loss leader to get more business.