Money fund assets inched lower in the latest week, the 4th decline in the past 5 weeks, but Prime money fund assets increased again and broke back over the $500 billion level. The Investment Company Institute's latest weekly "Money Market Fund Assets" report shows assets down by $137 billion, or -2.9%, year-to-date, with Institutional MMFs down $161 billion, or -5.0% and Retail MMFs up $24 billion, or 1.6%. Over the past 52 weeks, money fund assets are up by $58 billion, or 1.3%, with Retail MMFs rising by $65 billion (4.5%) and Inst MMFs falling by $7 billion (-0.2%). (For the month of August through 8/31, MMF assets increased by $34.0 billion to $5.031 trillion according to Crane's MFI XLS, which tracks a broader universe of funds than ICI. Crane Data's Prime asset total is currently $943.5 billion.) ICI's weekly release says, "Total money market fund assets decreased by $2.47 billion to $4.57 trillion for the week ended Wednesday, August 31, the Investment Company Institute reported.... Among taxable money market funds, government funds decreased by $12.69 billion and prime funds increased by $8.52 billion. Tax-exempt money market funds increased by $1.70 billion." ICI's stats show Institutional MMFs decreasing $6.1 billion and Retail MMFs increasing $3.7 billion in the latest week. Total Government MMF assets, including Treasury funds, were $3.959 trillion (86.7% of all money funds), while Total Prime MMFs were $506.9 billion (11.1%). Tax Exempt MMFs totaled $102.2 billion (2.2%). ICI explains, "Assets of retail money market funds increased by $3.68 billion to $1.49 trillion. Among retail funds, government money market fund assets decreased by $4.14 billion to $1.13 trillion, prime money market fund assets increased by $6.86 billion to $275.87 billion, and tax-exempt fund assets increased by $957 million to $90.88 billion." Retail assets account for just under a third of total assets, or 32.7%, and Government Retail assets make up 75.4% of all Retail MMFs. They add, "Assets of institutional money market funds decreased by $6.14 billion to $3.08 trillion. Among institutional funds, government money market fund assets decreased by $8.55 billion to $2.83 trillion, prime money market fund assets increased by $1.67 billion to $231.00 billion, and tax-exempt fund assets increased by $742 million to $11.32 billion." Institutional assets accounted for 67.3% of all MMF assets, with Government Institutional assets making up 92.1% 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 over $400 billion lower than Crane's asset series.)