Exchange-Traded Funds seized four of the top five slots in the US league of retail inflows in April compiled by data provider Financial Research Corporation, although two of them also saw the biggest outflows over the year to date, illustrating how quickly investors are switching in and out of them.

The list is headed by State Street Global Advisors' SPDR S&P 500 which received $2.74bn in April. This, however, only makes up some of the ground lost earlier this year, leading to a net loss of $2.6bn in the first four months of the year.