ICI's latest "Money Market Fund Assets" report shows assets jumping in the latest week, after a sharp drop due to quarterly taxes. Their release says, "Total money market fund assets increased by $50.10 billion to $4.51 trillion for the week ended Wednesday, September 22, the Investment Company Institute reported.... Among taxable money market funds, government funds increased by $48.05 billion and prime funds increased by $2.72 billion. Tax-exempt money market funds decreased by $669 million." Money fund assets are up by $217 billion, or 5.1%, year-to-date in 2021. Inst MMFs are up $313 billion (11.3%), while Retail MMFs are down $95 billion (-6.2%). ICI's stats show Institutional MMFs increasing $50.2 billion and Retail MMFs decreasing $0.1 billion in the latest week. Total Government MMF assets, including Treasury funds, were $3.956 trillion (87.6% of all money funds), while Total Prime MMFs were $469.4 billion (10.4%). Tax Exempt MMFs totaled $89.7 billion (2.0%). Over the past 52 weeks, money fund assets have increased by $100 billion, or 2.3%, with Retail MMFs falling by $93 billion (-6.1%) and Inst MMFs rising by $193 billion (6.7%). (Note that ICI's asset totals don't include a number of funds tracked by the SEC and Crane Data, so they're almost $400 billion lower than Crane's asset series.) ICI explains, "Assets of retail money market funds decreased by $125 million to $1.43 trillion. Among retail funds, government money market fund assets increased by $2.01 billion to $1.14 trillion, prime money market fund assets decreased by $1.63 billion to $214.90 billion, and tax-exempt fund assets decreased by $499 million to $78.49 billion." Retail assets account for just under a third of total assets, or 31.7%, and Government Retail assets make up 79.5% of all Retail MMFs. They add, "Assets of institutional money market funds increased by $50.23 billion to $3.08 trillion. Among institutional funds, government money market fund assets increased by $46.04 billion to $2.82 trillion, prime money market fund assets increased by $4.36 billion to $254.48 billion, and tax-exempt fund assets decreased by $170 million to $11.22 billion." Institutional assets accounted for 68.3% of all MMF assets, with Government Institutional assets making up 91.4% of all Institutional MMF totals.