Money market fund assets plummeted in the latest week as the Sept. 15 tax payment date sucked assets out. This is the sixth decrease in a row for MMFs, and their 14th decrease over the past 17 weeks. Assets broke below the $4.5 trillion level earlier this month for the first time since April 15. ICI's latest weekly "Money Market Fund Assets" report says, "Total money market fund assets decreased by $51.89 billion to $4.42 trillion for the week ended Wednesday, September 16, the Investment Company Institute reported.... Among taxable money market funds, government funds decreased by $43.24 billion and prime funds decreased by $7.17 billion. Tax-exempt money market funds decreased by $1.48 billion." ICI's stats show Institutional MMFs dropping $50.5 billion and Retail MMFs decreasing $1.4 billion. Total Government MMF assets, including Treasury funds, were $3.566 trillion (80.7% of all money funds), while Total Prime MMFs were $734.5 billion (16.6%). Tax Exempt MMFs totaled $116.2 billion (2.6%). ICI shows money fund assets up a still massive $784 billion, or 21.6%, year-to-date in 2020, with Inst MMFs up $626 billion (27.7%) and Retail MMFs up $159 billion (11.6%). Over the past 52 weeks, ICI's money fund asset series has increased by $1.014 trillion, or 30.0%, with Retail MMFs rising by $227 billion (17.6%) and Inst MMFs rising by $787 billion (37.6%). (Crane Data's separate and broader Money Fund Intelligence Daily data series shows total MF assets are down $118.8 billion in September (as of 9/16) to $4.791 trillion.) They explain, "Assets of retail money market funds decreased by $1.35 billion to $1.53 trillion. Among retail funds, government money market fund assets increased by $3.10 billion to $992.98 billion, prime money market fund assets decreased by $3.28 billion to $430.85 billion, and tax-exempt fund assets decreased by $1.17 billion to $104.99 billion." Retail assets account for just over a third of total assets, or 34.6%, and Government Retail assets make up 65.0% of all Retail MMFs. ICI adds, "Assets of institutional money market funds decreased by $50.54 billion to $2.89 trillion. Among institutional funds, government money market fund assets decreased by $46.34 billion to $2.57 trillion, prime money market fund assets decreased by $3.88 billion to $303.64 billion, and tax-exempt fund assets decreased by $316 million to $11.26 billion." Institutional assets, which broke below the $3.0 trillion level for the first time since April 22, accounted for 65.4% of all MMF assets, with Government Institutional assets making up 89.1% of all Institutional MMF totals.