The Investment Company Institute released its latest weekly "Money Market Fund Assets" report Thursday, which shows money fund assets rising $52.4 billion to a record $7.259 trillion. MMFs rose $17.2 billion last week, $3.8 billion the week before and $33.3 billion 3 weeks ago. MMF assets are up by $959 billion, or 15.2%, over the past 52 weeks (through 9/3/25), with Institutional MMFs up $548 billion, or 14.6% and Retail MMFs up $411 billion, or 16.1%. Year-to-date, MMF assets are up by $409 billion, or 6.0%, with Institutional MMFs up $180 billion, or 4.4% and Retail MMFs up $229 billion, or 8.4%. (Note: Register soon for our European Money Fund Symposium, which takes place Sept. 22-23 in Dublin, Ireland!)
ICI's weekly release says, "Total money market fund assets increased by $52.37 billion to $7.26 trillion for the week ended Wednesday, September 3.... Among taxable money market funds, government funds increased by $44.71 billion and prime funds increased by $5.87 billion. Tax-exempt money market funds increased by $1.79 billion." ICI's stats show Institutional MMFs increasing $33.5 billion and Retail MMFs increasing $18.9 billion in the latest week. Total Government MMF assets, including Treasury funds, were $5.915 trillion (81.5% of all money funds), while Total Prime MMFs were $1.206 trillion (16.6%). Tax Exempt MMFs totaled $138.2 billion (1.9%).
It explains, "Assets of retail money market funds increased by $18.90 billion to $2.96 trillion. Among retail funds, government money market fund assets increased by $12.84 billion to $1.86 trillion, prime money market fund assets increased by $4.65 billion to $975.56 billion, and tax-exempt fund assets increased by $1.42 billion to $125.27 billion." Retail assets account for 40.8% of the total, and Government Retail assets make up 62.9% of all Retail MMFs.
They add, "Assets of institutional money market funds increased by $33.47 billion to $4.29 trillion. Among institutional funds, government money market fund assets increased by $31.87 billion to $4.05 trillion, prime money market fund assets increased by $1.23 billion to $230.75 billion, and tax-exempt fund assets increased by $373 million to $12.96 billion." Institutional assets accounted for 59.2% of all MMF assets, with Government Institutional assets making up 94.3% of all institutional MMF totals.
According to Crane Data's separate Money Fund Intelligence Daily series, money fund assets increased by $30.1 billion in early September (through 9/3/25) to $7.633 trillion. Assets broke above $7.6 trillion for the first time on August 29 and hit a record high of $7.633 trillion on September 2, assets broke above $7.5 trillion for the first time less than a month ago, on August 4. Assets increased by $132.0 billion in August, $63.7 billion in July, $6.7 billion in June and $100.9 billion in May. They fell by $24.4 billion in April, but rose $2.8 trillion in March, $94.2 billion in February and $52.8 billion in January. They jumped $110.9 billion in December, $200.5 trillion in November, $97.5 billion in October and $149.8 billion last September. 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.
In other news, J.P. Morgan writes that, "Liquidity investors extend." They explain, "Just like that, September has arrived, and markets are now almost fully pricing in a policy rate cut later this month. In anticipation, money market investors have been extending into longer-dated maturities ahead of a potential restart to the easing cycle. Notably, government MMFs have lengthened their WAMs by 3.4 days to an average of 40 days, while prime funds have extended by 2.2 days to 29 days, over the past month."
The brief continues, "Both government and prime fund WAMs now stand at their highest levels this year, and at their longest since June 2021. While it's possible that MMFs could extend a bit further, money funds are also approaching the upper end of their range, especially for government MMFs. For context, looking back over the past 15 years, government WAMs peaked at around 47 days towards the end of 2020."
JPM says, "The extension in duration was evident across both T-bills and short-term credit markets. In fact, this week's 52-week T-bill auction saw end users take down a remarkable 83% of the supply, the largest on record. Similarly, the latest 13-week and 17-week auctions performed well, with end users taking 70% and 73% respectively, both above year-to date averages. Demand for longer-dated fixed rate bank CP/CDs also surged in recent weeks, with maturities of 6 months to 1 year accounting for over 50% of total volumes on average, reaching the highest levels since September 2023."
They state, "On a relative value basis, 6m fixed bank CP/CD yields are roughly in line with their FRN counterparts on a fixed equivalent basis ..., so the preference to go into floating vs fixed largely comes down to Fed expectations, which we should find out more about at the September FOMC meeting. While MMFs typically experience outflows of around $30bn in mid-September due to the corporate tax deadline, these outflows are relatively modest compared to the overall flows into and out of taxable MMFs, and absent any idiosyncratic events, are expected to have limited to no impact on bank CP/CD funding levels."
The piece adds, "Finally, as we discussed previously, it will be important to track MMF AUM flows, WAM positioning, and tri-party repo levels throughout the month, as outsized redemptions or significant extensions in maturities could spill over into slightly higher repo financing costs."
