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Savings & Income
Best Money Market Funds: Yields at Vanguard, Schwab and Fidelity
On September 28, 2026, Vanguard’s VMFXX had a 3.78% 7-day SEC yield at a 0.11% expense ratio, and it’s Vanguard’s default settlement fund. Merrill’s TFDXX yielded 3.77% and Schwab’s SWVXX 3.71%, while Fidelity’s default SPAXX yielded 3.47%. At Schwab, E*TRADE and Merrill, uninvested cash earns 0.01%.
Which Money Market Fund Fits You
Government money market fund yields at the big brokers ranged from 3.47% to 3.79% on September 28, 2026. The bigger difference is whether your broker puts uninvested cash into one for you.
Highest-yielding default
Vanguard VMFXX
3.78% 7-day SEC yield at a 0.11% expense ratio, and uninvested cash goes into it automatically.
See in comparison table ↑
No minimum
Schwab SWVXX
3.71% 7-day yield, 0.34% expense ratio and no minimum, but you have to buy it.
Schwab review →
Hands-off at Fidelity
Fidelity SPAXX
3.47% as the default core position. FDRXX yields more, 3.54%, at a lower 0.35% expense ratio.
See in comparison table ↑
Funds from $1
Merrill TFDXX
3.77% with a $1 minimum, bought by order. Merrill’s default sweep pays 0.01%.
See in comparison table ↑
Interest without a fund
Interactive Brokers
3.38% on IBKR Pro cash above the first $10,000, paid automatically.
Interactive Brokers review →Where Your Uninvested Cash Goes by Default
| Broker | Default for uninvested cash | Rate | On $50,000 a year |
|---|---|---|---|
| Vanguard | VMFXX money market settlement fund | 3.78% | About $1,890 |
| Fidelity | SPAXX money market core position | 3.47% | About $1,735 |
| Interactive Brokers (Pro) | Broker-held cash, first $10,000 unpaid | 3.38% above $10K | About $1,352 |
| Charles Schwab | Bank sweep | 0.01% | About $5 |
| E*TRADE | Bank sweep | 0.01% | About $5 |
| Merrill Edge | Bank of America sweep | 0.01% | About $5 |
Yields as of September 28, 2026 and sweep rates as of September 29, 2026, from each broker’s official pages, held for a full year. Yields change daily. At Schwab, E*TRADE and Merrill, buying a money market fund yourself earns about 3.5%–3.8% instead.
How To Read Money Market Numbers
7-day SEC yield
The standard yield
The fund’s income over the past 7 days, after expenses, shown as a yearly rate. It’s the fairest way to compare funds.
Expense ratio
What the fund keeps
Already taken out of the yield. SPAXX charges 0.42% and VMFXX 0.11%, which explains much of their yield gap.
Fund type
Government, Treasury or prime
Government and Treasury funds hold government debt; prime funds also hold corporate debt for slightly more yield and risk.
Settlement fund
Your account’s default
The fund your broker uses to hold cash between trades. Sales settle into it and purchases are paid from it.
What To Check Before You Choose a Fund
- Where your cash goes now. A 0.01% sweep can cost hundreds of dollars a year on a large balance.
- The 7-day SEC yield. Compare this figure, not an advertised or annualized one.
- The expense ratio. Between similar government funds, a lower expense ratio usually means a higher yield.
- Minimums. VMRXX needs $3,000; SWVXX and Merrill’s funds need little or nothing.
- Taxes. Treasury-only funds can be partly exempt from state income tax; municipal funds from federal tax.
- It’s not FDIC-insured. Money market funds aim to keep a $1 share price but can lose value. SIPC covers them if the broker fails.
How To Put Idle Cash in a Money Market Fund
- Check your default. Look up your broker’s sweep or settlement fund and its current rate.
- Pick a fund type. A government fund suits most cash; a Treasury fund may save state tax.
- Compare yield and expense ratio. Use the comparison table above.
- Buy the fund. At Schwab, E*TRADE and Merrill, place an order; there’s usually no commission on the broker’s own funds.
- Keep a small cash buffer. Leave enough in the sweep for pending trades and fees.
- Review when rates move. Compare with CDs and Treasury bills if you won’t need the cash for a while.
How We Compared
Yields and expense ratios come from each fund’s official fact sheet or fund page, and sweep rates from each broker’s cash pages, checked September 29, 2026 and summarized in the comparison table. Webull, Moomoo and tastytrade aren’t included because no money market fund offering could be confirmed on their pages; their cash sweeps are compared on the high-yield cash page. Firms marked “Special Offer” are AInvest partners, and AInvest may be compensated when you open an account through this page. Past yields don’t guarantee future results.
FAQ & Glossary
Which money market fund pays the most?
Among the broker funds checked on September 28, 2026, Vanguard Cash Reserves Federal (VMRXX) had a 3.79% 7-day SEC yield and Vanguard Federal Money Market (VMFXX) 3.78%, followed by Merrill’s TFDXX at 3.77% and Schwab’s SWVXX at 3.71%. Fidelity’s SPAXX yielded 3.47%. Yields change daily.
What is a 7-day SEC yield?
The 7-day SEC yield is a standard measure of a money market fund’s income over the past seven days, after fund expenses, expressed as an annual rate. Because every fund calculates it the same way, it’s the best number for comparing money market funds.
What is a money market settlement fund?
A settlement fund is the money market fund a broker uses to hold cash in your account between trades: money from sales settles into it and purchases are paid from it. At Vanguard it’s VMFXX and at Fidelity usually SPAXX. Schwab, E*TRADE and Merrill use bank sweeps paying 0.01% instead.
Are money market funds guaranteed like bank deposits?
No. They're designed for stability, but they're investment products. Safety depends on fund holdings and sponsor quality, not insurance.
When are money market funds better than high-yield savings?
They can win on net yield and integration with your brokerage, but HYSA may have easier access and FDIC insurance.
What is Money Market Fund?
A mutual fund that invests in short-term, low-risk securities like Treasuries and commercial paper. Designed for stability and liquidity.
What is Expense Ratio?
The annual fee a fund charges as a percentage of your investment, deducted from returns. Lower expense ratios mean higher net yields.
What is Gross Yield vs. Net Yield?
Gross yield is the fund's investment return before fees. Net yield is what you actually receive after expense ratio is deducted.
What is Commercial Paper?
Short-term corporate debt (typically under 270 days). Used by prime money market funds; higher yield but more credit risk than Treasuries.
What is Redemption Gate?
The right of a fund to delay or limit redemptions during market stress. Money market funds can impose gates if the fund is destabilized.
What is NAV (Net Asset Value)?
The price per share of a fund, calculated as total fund value minus liabilities, divided by shares outstanding. Money market funds aim to keep NAV at $1.00.