The Investment Company Institute released its latest weekly "Money Market Fund Assets" report yesterday, which shows MMF assets fell in the latest week after hitting their highest levels since April 2010 the prior week. Prime assets continued their solid and steady rebound, while Government funds plunged. Overall assets are now up $28 billion, or 1.0%, YTD, and they've increased by $141 billion, or 5.2%, over 52 weeks. Prime assets have risen for 11 weeks in a row. ICI writes, "Total money market fund assets decreased by $17.89 billion to $2.87 trillion for the week ended Wednesday, September 19, the Investment Company Institute reported.... Among taxable money market funds, government funds decreased by $22.69 billion and prime funds increased by $4.50 billion. Tax-exempt money market funds increased by $307 million." Total Government MMF assets, which include Treasury funds too, stand at $2.195 trillion (76.6% of all money funds), while Total Prime MMFs stand at $538.7 billion (18.8%). Tax Exempt MMFs total $131.4 billion, or 4.6%. They explain, "Assets of retail money market funds increased by $1.73 billion to $1.06 trillion. Among retail funds, government money market fund assets decreased by $25 million to $633.42 billion, prime money market fund assets increased by $1.56 billion to $305.69 billion, and tax-exempt fund assets increased by $196 million to $123.27 billion." Retail assets account for over a third of total assets, or 37.1%, and Government Retail assets make up 59.6% of all Retail MMFs. ICI's release adds, "Assets of institutional money market funds decreased by $19.62 billion to $1.80 trillion. Among institutional funds, government money market fund assets decreased by $22.67 billion to $1.56 trillion, prime money market fund assets increased by $2.94 billion to $233.05 billion, and tax-exempt fund assets increased by $111 million to $8.08 billion." Institutional assets account for 62.9% of all MMF assets, with Government Inst assets making up 86.6% of all Institutional MMFs.