The Investment Company Institute's latest weekly "Money Market Fund Assets" report shows assets rising for the fifth week in a row and the sixth week out of the past seven. Over the past 5 weeks, money fund assets have increased by $81.4 billion, and over the past seven weeks assets are up $118.1 billion. Money fund assets are up by $339 billion, or 7.9%, YTD in 2021. (This follows a gain of $665.0 billion, or 18.3%, in 2020.) Inst MMFs are up $425 billion (15.3%), while Retail MMFs are down $86 billion (-5.6%). Over the past 52 weeks, money fund assets have increased by $293 billion, or 6.7%, with Retail MMFs falling by $83 billion (-5.4%) and Inst MMFs rising by $376 billion (13.3%). ICI's release says, "Total money market fund assets increased by $14.70 billion to $4.64 trillion for the week ended Wednesday, December 8, the Investment Company Institute reported.... Among taxable money market funds, government funds increased by $15.29 billion and prime funds decreased by $206 million. Tax-exempt money market funds decreased by $385 million." ICI's stats show Institutional MMFs increasing $6.7 billion and Retail MMFs increasing $8.0 billion in the latest week. Total Government MMF assets, including Treasury funds, were a record $4.104 trillion (88.5% of all money funds), while Total Prime MMFs were $444.7 billion (9.6%). Tax Exempt MMFs totaled $86.8 billion (1.9%). ICI explains, "Assets of retail money market funds increased by $8.04 billion to $1.44 trillion. Among retail funds, government money market fund assets increased by $9.43 billion to $1.16 trillion, prime money market fund assets decreased by $1.34 billion to $204.40 billion, and tax-exempt fund assets decreased by $54 million to $76.81 billion." Retail assets account for just under a third of total assets, or 31.1%, and Government Retail assets make up 80.5% of all Retail MMFs. They add, "Assets of institutional money market funds increased by $6.67 billion to $3.20 trillion. Among institutional funds, government money market fund assets increased by $5.86 billion to $2.95 trillion, prime money market fund assets increased by $1.13 billion to $240.32 billion, and tax-exempt fund assets decreased by $330 million to $9.97 billion." Institutional assets accounted for 68.9% of all MMF assets, with Government Institutional assets making up 92.2% of all Institutional MMF totals. (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.)