APY stands for Annual Percentage Yield, which represents how much interest you would earn on an amount of money invested for an entire year if the rate were to remain constant.

 
The APY allows you to compare the rates of interest payable on different accounts regardless of when, and how, they pay interest. 

For example, if you deposited €10,000 into a money market fund with an APY of 3%, this would mean you would have €10,001.64 on day 3, whilst earning interest on interest (i.e. compounding).

Day 1: €10,000

Day 2: €10,000 + (€10,000 X 3%/365) = €10,000.82

Day 3: €10,000.82 + (€10,000.82 X 3%/365) = €10,001.64

The APY of each currency fund changes on a daily basis based on market conditions as well as the composition of the underlying investments. Rates will normally track central banks’ rates so for example if the European Central Bank increases rates, the APY for EUR of the Money Market fund would also increase with time.