ICI's latest weekly "Money Market Fund Assets" report shows assets rising for the 8th week in a row and the 9th week out of the past 10. Over the past 8 weeks, money fund assets have increased by $150.6 billion, and over the past 10 weeks assets they are up $187.2 billion. Money fund assets are up by $408 billion, or 9.5%, YTD in 2021. (This follows a gain of $665.0 billion, or 18.3%, in 2020.) Inst MMFs are up $465 billion (16.8%), while Retail MMFs are down $57 billion (-3.7%). Over the past 52 weeks, money fund assets have also increased by $408 billion, or 9.5%, with Retail MMFs falling by $57 billion (-3.7%) and Inst MMFs rising by $465 billion (16.8%). ICI's release says, "Total money market fund assets increased by $38.98 billion to $4.71 trillion for the week ended Wednesday, December 29, the Investment Company Institute reported today. Among taxable money market funds, government funds increased by $38.67 billion and prime funds increased by $507 million. Tax-exempt money market funds decreased by $197 million." ICI's stats show Institutional MMFs increasing $39.0 billion and Retail MMFs increasing $6.4 billion in the latest week. Total Government MMF assets, including Treasury funds, were a record $4.175 trillion (88.7% of all money funds), while Total Prime MMFs were $443.0 billion (9.4%). Tax Exempt MMFs totaled $86.6 billion (1.8%). ICI explains, "Assets of retail money market funds increased by $6.43 billion to $1.47 trillion. Among retail funds, government money market fund assets increased by $5.82 billion to $1.19 trillion, prime money market fund assets increased by $456 million to $205.12 billion, and tax-exempt fund assets increased by $154 million to $77.39 billion." Retail assets account for just under a third of total assets, or 31.2%, and Government Retail assets make up 80.8% of all Retail MMFs. They add, "Assets of institutional money market funds increased by $32.55 billion to $3.24 trillion. Among institutional funds, government money market fund assets increased by $32.85 billion to $2.99 trillion, prime money market fund assets increased by $51 million to $237.92 billion, and tax-exempt fund assets decreased by $351 million to $9.20 billion." Institutional assets accounted for 68.8% of all MMF assets, with Government Institutional assets making up 92.4% 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.)