Money Market Fund Statistics (2026)

US money market funds held $7.92 trillion as of October 14, 2026, according to the Investment Company Institute, down from $7.96 trillion a week earlier and $7.89 trillion on September 30 (see the table below). The total slipped about $40.5 billion on the week, a normal wobble in a market this size.

That figure covers taxable and tax-exempt funds and splits three ways by type and two ways by investor. Government funds ($6.52 trillion) tower over prime ($1.24 trillion) and tax-exempt ($168 billion). Note that Crane Data, which counts more funds, reported a higher total of $8.39 trillion as of September 30, 2026 in its Form N-MFP holdings summary.

Money funds have roughly doubled in size in a few years. Assets first crossed $3 trillion in January 2008, reached $5 trillion during the March 2020 COVID rush, and hit $7 trillion for the first time in the week ended March 5, 2025 (see the chart below).

The engine has been interest rates. When the Fed pushed short-term rates above 5% in 2023, cash suddenly paid, and both households and institutions parked trillions in money funds. Even after the 2025 rate cuts trimmed yields, the money largely stayed put through 2026.

The market is overwhelmingly government funds, which hold about 82.3% of all assets and invest in Treasury bills, agency debt, and repurchase agreements backed by them (see the chart below). Prime funds, which also buy commercial paper and bank paper, are 15.6%, and tax-exempt (municipal) funds just 2.1%.

That tilt is a legacy of the 2016 SEC reforms, which imposed floating share prices and liquidity fees on institutional prime funds. Many big investors fled to government funds for their stable $1.00 share price, permanently reshaping the mix toward government.

Institutions own the majority of money fund assets: $4.80 trillion (60.6%) versus $3.12 trillion (39.4%) for retail investors (see the table below). But the two groups hold very different products. Institutional money is 94.5% government, which reflects the flight from prime after 2016.

Retail investors, by contrast, still hold a lot of prime: retail prime funds are $986 billion, about 80% of all prime assets, versus just $249 billion held by institutions. Retail also splits toward government ($1.98 trillion), which is where most brokerage sweep cash lands.

On the institutional side, the ICI Fact Book classifies holders by type. Business corporations are the single largest group at about $1.10 trillion (44.9%), just ahead of financial institutions at $1.03 trillion (42.2%) (see the table below).

Nonprofit organizations hold about $210 billion (8.6%) and a residual Other category about $103 billion (4.2%). Corporations use money funds as a treasury tool: a place to hold operating cash and earn a yield while keeping same-day liquidity. This classification covers a subset of institutional accounts.

The average money fund yielded 3.70% (7-day, annualized, current) as of October 15, 2026, as measured by the Crane 100 index (see the chart below). That is up from about 3.45% in July but still well below the cycle peak of 5.20% reached in November 2023, when the federal funds rate was at its highest.

Yields track the Fed almost mechanically because money funds hold securities that mature in weeks. As the Fed cut three times in late 2025, to a 3.50-3.75% target range, the Crane 100 slid from above 4% to the mid-3s. On September 17, 2026 the Fed raised the range by a quarter point to 3.75-4.00%, and money fund yields moved up with it (Federal Reserve).

The descent was steady rather than sharp. From 5.20% in late 2023, the Crane 100 average eased to 4.28% by the end of 2024, 4.13% by mid-2025, 3.58% by the end of 2025, and about 3.45% by July 2026 (see the table below). It then turned up, to 3.70% by October 15, 2026, after the Fed's September rate increase.

Each step followed a Fed rate change, since money funds pass through changes in short rates within roughly a month. The takeaway for savers: money fund yields are not fixed; they float with policy in both directions, so today's rate is a snapshot, not a promise.

Money funds pulled in about $672 billion of net new cash in 2025, per the ICI Fact Book, split between institutional ($445 billion) and retail ($227 billion) investors. Government funds captured the lion's share at $558 billion, with prime funds adding about $102 billion.

Those inflows are why assets kept setting records even as yields fell. Investors also reinvested most of their earnings: of about $304 billion in 2025 dividends, roughly $229 billion (75%) was reinvested rather than withdrawn, compounding balances higher.

A striking counter-trend sits behind the record assets: the number of money market funds keeps shrinking. There were 364 US money funds in 2019, falling to 291 in 2022 and about 265 in 2025 (see the table below).

So the industry is consolidating into fewer, far larger funds. Average assets per fund have exploded from under $10 billion in 2019 to roughly $30 billion in 2026. Scale matters here: bigger funds spread fixed costs over more assets, which supports lower fees and steadier liquidity.

The biggest single funds are enormous. Fidelity's Government Money Market Fund (SPAXX) and Schwab's Value Advantage (SWVXX) each run in the neighborhood of $400 billion, and Vanguard's Federal Money Market Fund (VMFXX) is about $376 billion (see the table below).

These individual-fund figures come from filings and aggregators as of various 2026 dates, so treat them as approximate and illustrative of scale rather than a precise ranking. Fidelity, Vanguard, JPMorgan, Goldman Sachs, and Schwab are the dominant sponsors by combined assets.

Under the hood, money funds are short-term lending machines. Government funds hold Treasury bills, agency securities, and repurchase agreements collateralized by them; the US Treasury's Office of Financial Research tracks these portfolios in its Money Market Fund monitor.

Repo is central: money funds are among the largest lenders in the overnight repo market and heavy users of the Fed's facilities. Government-fund weighted average maturity ran about 41 days in 2025, meaning portfolios turn over roughly monthly, which is exactly why their yields follow the Fed so closely.

The prime-versus-government split is the most important structural story in the market. Before 2016, prime funds (which buy corporate and bank paper for a bit more yield) were far larger. Post-crisis SEC rules forcing floating NAVs and fees on institutional prime funds triggered a mass exodus.

The result: government funds now hold more than five times the assets of prime funds, and institutional prime is a small $248 billion niche. Retail investors, who kept a stable $1.00 price, are the ones who stayed in prime, which is why retail holds about 80% of prime assets today.

For an emergency fund or near-term savings, a money market fund is a reasonable home: it typically yields close to short-term rates (about 3.70% in October 2026) with a stable $1.00 share price and daily liquidity. Government funds are the most conservative flavor.

Two cautions. Money funds are not FDIC insured and their yield floats with the Fed, so it can fall fast when rates drop. And cash is for money you may need soon, not long-term growth: over decades, stocks have far out-returned cash, so a big money-fund balance can be a drag if it is really long-horizon money.