The net retail sales figures for equity funds were the highest seen since the £2.5bn inflow recorded in June 2013 as the market rebounded sharply from its 2009 lows.
The April 2017 sales were focused in global funds, which sold £1.2bn in April compared to a rolling monthly average of £314m according to the Investment Association figures, which track UK investor buying behaviour.
The next three most popular regions for equity-fund sales were the US, Europe and Japan which all received more than £200m of inflows.
But Asian equity funds failed to make hay during the equity sales boom, with funds focused on the region losing £47m of client money.
As equities rode high, other asset classes also enjoyed a positive month with mixed-asset funds reporting net retail sales of £1bn and bond funds receiving £225m.
Money market funds received £832m and property funds received £69m in net retail inflows.