Investors have pumped cash into US money market funds for a fifth week in a row, the latest sign of strong demand ahead of a potential interest rate cut by the Federal Reserve. About $37 billion flowed into US money market funds in the week to September 4, bringing recent inflows to about $165bn, according to the Investment Company Institute. Total assets rose to a record $6.30 trillion from $6.26 trillion the week before. Despite the strong demand, debate is heating up over whether money market funds will remain popular once US policymakers start cutting interest rates. The Federal Reserve is widely expected to cut interest rates later this month. The attractive returns from high interest rates have fuelled a surge in the size of US money market funds.