Money market mutual fund assets surged by $76.4 billion on Friday (12/26), breaking the $8.1 trillion barrier for the first time ever and hitting a record $8.104 trillion, according to our Money Fund Intelligence Daily. Assets have risen $94.8 billion in the week through Friday and they've jumped by $121.7 billion in December month-to-date (through 12/26). Year-to-date in 2025, they've gained $930.3 billion (13.0%) in assets. MMF assets increased by $132.8 billion in November, $142.1 billion in October, $105.2 billion in September and $132.0 billion in August. They rose by $63.7 billion in July, $6.7 billion in June and $100.9 billion in May. But MMFs decreased $24.4 billion in April. Assets increased by $2.8 billion in March, $94.2 billion in February, $52.8 billion in January, and $110.9 billion last December. (Note: Happy Holiday and Happy New Year from Crane Data and Money Fund Intelligence!)
Money fund yields (7-day, annualized, simple, net) decreased by 1 bp to 3.57% on average during the week ended Friday, December 26 (as measured by our Crane 100 Money Fund Index), after decreasing 8 bps the week prior. Fund yields should move lower in coming days as they digest the remainder of the Fed's Dec. 10 25 bps rate cut. Yields were 3.78% on 11/30, 3.90% on 10/31, 3.94% on 9/30, 4.11% on 8/31, 4.12% on 7/31, 4.13% on 6/30, 4.10% on 5/31, 4.13% on 4/30/25, 4.14% on 3/31/25 and 4.28% on average on 12/31/24. MMFs averaged 4.75% on 9/30/24, 5.10% on 6/28/24, 5.14% on 3/31/24 and 5.20% on 12/31/23.
The broader Crane Money Fund Average, which includes all taxable funds tracked by Crane Data (currently 679), shows a 7-day yield of 3.47%, down 2 bps in the week through Friday. Prime Inst money fund yields were down 1 bp at 3.66% in the latest week. Government Inst MFs were down 3 bps at 3.57%. Treasury Inst MFs were down 2 bps at 3.53%. Treasury Retail MFs currently yield 3.30%, Government Retail MFs yield 3.27% and Prime Retail MFs yield 3.46%, Tax-exempt MF 7-day yields were up 7 bps to 2.76%.
Weighted average maturities were at 39 days for the Crane MFA and 40 days the Crane 100 Money Fund Index. According to Monday's Money Fund Intelligence Daily, with data as of Friday (12/26), 132 money funds (out of 789 total) yield under 3.0% with $125.5 billion in assets, or 1.5%; 656 funds yield between 3.00% and 3.99% ($7.977 trillion, or 98.4%); and just 1 fund still yields over 4.0% ($1.3 billion, or 0.0%).
Our Brokerage Sweep Intelligence Index, an average of FDIC-insured cash options from major brokerages, was unchanged at 0.30%, after falling 1 basis point the week prior. The latest Brokerage Sweep Intelligence, with data as of December 26, shows one change over the past week. Raymond James lowered rates for accounts of $1K to $249K to 0.03%, to 0.07% for accounts of $250K to $499K, to 0.1% for accounts of $500K to $999K, to 1.00% for accounts of $1 million to $4.9 million and to 1.50% for accounts of $10 million and greater. Three of the 10 major brokerages tracked by our BSI offer rates of 0.01% for balances of $100K (and lower tiers). These include: E*Trade, Merrill Lynch and Morgan Stanley.
In related news, Vanguard posted an article titled, "Understanding high-yield savings accounts and how rates work." It states, "A high-yield savings account works like any other bank or credit union account, but typically offers a higher interest rate compared with a traditional savings account. You can use compound interest calculators to help determine your savings over time. Different factors can affect your savings growth, so it's important to consider them when choosing an account."
They ask, "What makes a high-yield savings account 'high yield'?" Vanguard answers, "The main factor that makes a savings account 'high yield' is the interest rate. While some traditional savings accounts offer an annual percentage yield (APY) as low as 0.01%, a high-yield savings account could offer a much greater amount. Many high-yield savings accounts are offered by digital banks and financial institutions. They have lower overhead costs since they don't have physical branches, and they can pass those savings on to clients in the form of higher interest rates."
A section titled, "Factors that affect your savings growth," explains, "Various elements can affect your savings growth over time. These can include: APY rates. Higher APY rates can lead to greater earnings over time. Digital banks and specialized accounts like CDs and money market funds often offer better rates; Account fees. Lower account maintenance fees can help you save money over time; Compounding frequency impact. More frequent compounding (e.g., daily, monthly) results in higher earnings compared with less frequent compounding (e.g., quarterly, annually)."
They also cite: "Initial deposit and additional contributions. Larger initial deposit amounts and higher contribution amounts will increase how much interest you can earn; Inflation. When prices rise and your purchasing power decreases, you'll want to know how to navigate times of rising inflation since ideally you'll want the interest in your savings to be higher than inflation; Taxes. Interest is generally taxed as ordinary income. Knowing the tax implications of your interest earnings can help you decide which types of savings accounts or investments offer the best net benefits."
The piece also asks, "What's the difference between the Vanguard Cash Plus Account and a high-yield savings account?" It states, "While Vanguard doesn't offer a high-yield savings account, we do offer the Vanguard Cash Plus Account, which is Vanguard's high-yield savings account alternative that offers a competitive APY on your cash, flexible investment options, and FDIC insurance on the bank sweep."
It adds, "Vanguard Cash Plus offers 2 ways for you to divvy up your cash. The first option allows you to keep your money in the bank sweep program, where your balances will be in one or more program banks and eligible for FDIC coverage. With the second option, you can diversify your money across 5 Vanguard money market funds that invest in short-term, high-quality debt that's eligible for SIPC insurance."
