Money market mutual fund assets, which broke above $2.8 trillion last week, continued to jump in the latest week, as assets of Retail MMFs broke above $1.0 trillion for the first time since April 2010. The Investment Company Institute's latest "Money Market Fund Assets" report shows that year-to-date, MMF assets have increased by $112 billion, or 4.1%. Money fund assets are showing their biggest annual increase since 2009. ICI's numbers also show Prime money market fund assets rose for their 9th week in a row and their 16th week in the past 19. They've now increased by $73.4 billion, or 19.5%, year-to-date. ICI writes, "Total money market fund assets increased by $33.75 billion to $2.84 trillion for the week ended Wednesday, December 13, the Investment Company Institute reported today. Among taxable money market funds, government funds increased by $31.31 billion and prime funds increased by $1.97 billion. Tax-exempt money market funds increased by $479 million." Total Government MMF assets, which include Treasury funds too, stand at $2.249 trillion (79.2% of all money funds), while Total Prime MMFs stand at $461.2 billion (16.2%). Tax Exempt MMFs total $130.6 billion, or 4.6%. They explain, "Assets of retail money market funds increased by $4.58 billion to $1.00 trillion. Among retail funds, government money market fund assets increased by $3.55 billion to $608.94 billion, prime money market fund assets increased by $586 million to $267.08 billion, and tax-exempt fund assets increased by $445 million to $124.69 billion." Retail assets account for over a third of total assets, or 35.2%, and Government Retail assets make up 60.9% of all Retail MMFs. ICI's release adds, "Assets of institutional money market funds increased by $29.17 billion to $1.84 trillion. Among institutional funds, government money market fund assets increased by $27.75 billion to $1.64 trillion, prime money market fund assets increased by $1.38 billion to $194.14 billion, and tax-exempt fund assets increased by $34 million to $5.90 billion." Institutional assets account for 64.8% of all MMF assets, with Government Inst assets making up 89.1% of all Institutional MMFs.