Originally Posted by
zyxlsy
My guess is that Capital One's posting date rates were different from the ones that OP thought were the actual posting rates. Maybe if we find another time when currency fluctuation isn't huge, we can see Capital One rates matching MC rates?
My experience with Chase MC IHG card is that it always uses the MC rates.
The Chase IHG MC is about the mid-rate (as per xe.com), while the Chase Visa cards are worse. Not 2.6% worse, but definitely worse.
See this
Chase foreign exchange rates thread.