Originally Posted by mizzou1

March 7 was a weekend day and Euro had a sharp decrease in value in March 6 (from 1.103 to 1.084). Since March 7 was a weekend day, effective currency exchange rates is usually picked from a time at previous business day and is kept about constant during the weekend. It seems that Visa has selected the most unfavorable rate and Mastercard has selected a favorable mid rate (or perhaps a rate based on the exact time of transaction). Such drastic changes in currency exchange rate are rare to happen for stable currencies, thus the difference between Visa and Mastercard rarely matters. But if somebody is making a transaction in countries with volatile exchange rates, the difference between Visa and Mastercard may be worth considering.