The prime minister of Greece and the president of France said last week that they expect a new bailout for Greece to be agreed before the end of August. Even though Germany is not publicly onboard with them, the optimism from Paris and Athens helped improve sentiment towards the euro.
Sentiment towards the US dollar was improved even more by a Federal Reserve president who said only a "significant deterioration" in the US economy would prevent him voting for higher interest rates next month. And sentiment towards sterling slumped when it was revealed that only one member of the MPC voted for a rate increase in August.
So the dollar was the top performer among the trio, strengthening by a quarter of a cent against the euro, and the pound was down by half a euro cent.