The U.S. Securities and Exchange Commission published its latest monthly "Money Market Fund Statistics" summary, which shows that total money fund assets decreased by $55.4 billion in September 2026 to $8.384 trillion, after increasing to $8.440 trillion the month prior and hitting a record $8.442 trillion in June. The SEC shows Prime MMFs decreased $3.2 billion in September to $1.369 trillion, Govt & Treasury funds decreased $58.6 billion to $6.855 trillion and Tax Exempt funds increased $6.4 billion to $161.1 billion. Taxable and Tax Exempt MMF yields were higher in September. The SEC's Division of Investment Management summarizes monthly Form N-MFP data and includes asset totals and averages for yields, liquidity levels, WAMs, WALs, holdings, and other money market fund trends. We review their latest numbers below. (Our MFI XLS monthly shows money fund assets decreasing $52.4 billion in September 2026 to $8.297 trillion. In October month-to-date through 10/22, total money fund assets have increased by $60.3 billion to $8.354 trillion, according to Crane Data's separate, and slightly smaller, MFI Daily series.)
September's asset decrease follows an increase of $52.7 billion in August, a decrease of $55.6 billion in July, an increase of $54.1 billion in June, an increase of $200.7 billion in May, a decrease of $102.3 billion in April, a decrease of $50.7 billion in March, an increase of $123.7 billion in February, $36.6 billion in January, $125.0 billion in December, $125.1 billion in November, $153.2 billion in October and $106.0 billion last September. Over the 12 months through 9/30/26, total MMF assets have increased by $607.2 billion, or 7.8%, according to the SEC's series.
The SEC's stats show that of the $8.384 trillion in assets, $1.369 trillion was in Prime funds, down $3.2 billion in September. Prime assets were up $1.5 billion in August, down $23.5 billion in July, up $21.5 billion in June, up $16.1 billion in May, down $26.2 billion in April, down $0.5 billion in March, up $18.2 billion in February, $22.4 billion in January, $1.2 billion in December, $3.1 billion in November, $9.1 billion in October and $6.2 billion last September. Prime funds represented 16.3% of total assets at the end of September. They've increased by $39.6 billion, or 3.0%, over the past 12 months. (Note that the SEC's series includes a number of internal money funds not tracked by ICI, though Crane Data includes most of these assets in its collections.)
Government & Treasury funds totaled $6.855 trillion, or 81.8% of assets. They decreased $58.6 billion in September, increased $52.0 billion in August, decreased $33.3 billion in July, increased $31.1 billion in June, increased $183.5 billion in May, decreased $75.9 billion in April, decreased $52.0 billion in March, increased $104.5 billion in February, increased $23.1 billion in January, increased $117.3 billion in December, increased $115.4 billion in November, increased $142.1 billion in October and increased $97.8 billion last September. Govt & Treasury MMFs are up $549.3 billion over 12 months, or 8.7%. Tax Exempt Funds increased $6.4 billion to $161.1 billion, or 1.9% of all assets. The number of money funds was 296 in September, up 1 from the previous month and up 17 funds from a year earlier.
Yields for Taxable and Tax Exempt MMFs were higher in September. The Weighted Average Gross 7-Day Yield for Prime Institutional Funds on September 30 was 4.04%, up 19 bps from the prior month. The Weighted Average Gross 7-Day Yield for Prime Retail MMFs was 4.04%, up 19 bps from the previous month. Gross yields were 3.92% for Government Funds, up 18 bps from last month. Gross yields for Treasury Funds were up 16 bps at 3.92%. Gross Yields for Tax Exempt Institutional MMFs were up 94 basis points to 3.46% in September. Gross Yields for Tax Exempt Retail funds were up 79 bps to 3.26%.
The Weighted Average 7-Day Net Yield for Prime Institutional MMFs was 3.94%, up 19 bps from the previous month and down 25 bps from 9/30/25. The Average Net Yield for Prime Retail Funds was 3.77%, up 18 bps from the previous month and down 27 bps since 9/30/25. Net yields were 3.71% for Government Funds, up 18 bps from last month. Net yields for Treasury Funds were up 15 bps from the previous month at 3.71%. Net Yields for Tax Exempt Institutional MMFs were up 92 bps from August to 3.33%. Net Yields for Tax Exempt Retail funds were up 79 bps at 3.03% in September. (Note: These averages are asset-weighted.)
WALs were mixed and WAMs were mostly lower in September. The average Weighted Average Life, or WAL, was 56.4 days (down 2.7 days) for Prime Institutional funds, and 51.4 days for Prime Retail funds (up 1.2 days). Government fund WALs averaged 93.4 days (up 1.1 days) while Treasury fund WALs averaged 91.0 days (up 0.3 days). Tax Exempt Institutional fund WALs were 4.4 days (down 0.7 days), and Tax Exempt Retail MMF WALs averaged 32.3 days (unchanged).
The Weighted Average Maturity, or WAM, was 28.6 days (down 3.4 days from the previous month) for Prime Institutional funds, 28.8 days (down 4.6 days from the previous month) for Prime Retail funds, 34.3 days (down 1.4 days from previous month) for Government funds, and 41.8 days (up 0.5 days from previous month) for Treasury funds. Tax Exempt Inst WAMs were down 0.7 days at 4.4 days, while Tax Exempt Retail WAMs were down 0.1 days from previous month at 31.5 days.
Total Daily Liquid Assets for Prime Institutional funds were 49.1% in September (up 1.7% from the previous month), and DLA for Prime Retail funds was 45.8% (down 0.8% from previous month) as a percent of total assets. The average DLA was 60.8% for Govt MMFs and 94.6% for Treasury MMFs. Total Weekly Liquid Assets was 64.6% (down 0.5% from the previous month) for Prime Institutional MMFs, and 60.8% (down 1.0% from the previous month) for Prime Retail funds. Average WLA was 75.7% for Govt MMFs and 99.2% for Treasury MMFs.
Note that the SEC made a number of changes to their monthly release in April 2025, so we're no longer publishing a number of tables. A press release titled, "SEC Publishes New Data and Analysis About Registered Investment Companies and Money Market Funds," states, "The Securities and Exchange Commission ... published new data and analysis in a pair of reports that provide the investing public with updated key information about registered investment companies and money market funds. 'It is important that the Commission publicly shares the information it collects in a clear and transparent way,' says Acting Chairman Mark Uyeda. 'These two reports will provide the public with key information about the approximately $41.5 trillion investors trust to funds and the approximately $7.39 trillion invested in money market funds.'"
The SEC says, "Money Market Fund Statistics is an enhanced version of the money market funds report generated by the Division of Investment Management. This report contains additional statistical analysis and enhancements, as well as certain metrics based on Form N-MFP data. The modifications to the report are designed to further facilitate the public's ability to efficiently review, digest, and use aggregate information about the money market fund industry by including summaries of more money market fund data, including information about internal affiliated funds, portfolio investments, flows, and industry concentration. The report extends the downloadable historical statistical series of data back to 2010."
Tim Husson, who leads the SEC's Division of Investment Management's Analytics Office, adds, "Forms N-MFP and N-CEN provide insights into key areas of the investment company industry. The reports reflect our continued dedication to enhance the public's use of important information about the industry."
