Managers of US money market funds are increasingly shortening the maturities of their assets amid uncertainty over the Federal Reserve's monetary policy outlook. According to research firm Crane Data, the industry-wide Crane Money Fund Average weighted average maturity stood at 38 days as of the 10th, down from 42 days a month earlier, while the Crane 100 Money Fund Index, which tracks major money market funds, saw its weighted average maturity fall to 40 days in July from 44 days in June. Meanwhile, inflows into money market funds continue, with Investment Company Institute data showing total assets under management hit a record high of roughly 8 trillion dollars in the first week of July. Managers are directing some of the inflows into floating-rate notes, with holdings of floating-rate US government securities reaching a record 523 billion dollars at the end of June, up 32 billion dollars from the previous month. Use of repurchase agreements also expanded, with repo balances rising by 68 billion dollars to 3.06 trillion dollars as of June 30, accounting for 37.2 percent of total assets, though the appeal of overnight repos has diminished as repo rates are pushed lower by inflows related to the Fed's reserve management. Against this backdrop, money market funds reduced their holdings of Treasury bills, which fell by 96 billion dollars from the previous month to 3.3 trillion dollars at the end of June, yet they remain the largest investment category at 39.9 percent of total assets.