Short answer: SPAXX is the Fidelity Government Money Market Fund — the default “core position” that holds your uninvested cash and pays you interest while it sits there. It’s not a bank account and it’s not FDIC insured; it’s a mutual fund that’s SIPC-protected instead. Fidelity puts new deposits and sale proceeds into SPAXX automatically so your cash isn’t sitting idle earning nothing. As of September 25, 2026, SPAXX’s 7-day yield was 3.46% (per Fidelity’s fund page) (check Fidelity’s SPAXX fund page for the current rate, since it moves with short-term interest rates). You can spend or invest that cash anytime — it isn’t locked up.
SPAXX at a Glance
| Item | Figure |
|---|---|
| Fund | Fidelity Government Money Market Fund (SPAXX) |
| 7-day yield | 3.46% as of 09/25/2026 |
| Expense ratio (gross) | 0.42% as of 06/29/2026 |
| Net asset value (NAV) | $1.00 as of 09/25/2026 |
| Minimum to invest | $0.00 |
| Objective | Seeks as high a level of current income as is consistent with preservation of capital and liquidity |
Figures are from Fidelity’s SPAXX fund page and change over time, so check the page for today’s numbers.
Why Did Fidelity Put My Money in SPAXX?
You didn’t do anything wrong, and nothing is stuck. SPAXX is Fidelity’s default core position — the holding place for any cash in your brokerage, IRA, or cash management account that isn’t currently invested in a stock, ETF, mutual fund, or option. Every dollar you deposit, every dividend you receive, and every sale you make lands in SPAXX until you decide what to do with it next.
Instead of that cash sitting there earning nothing, Fidelity automatically invests it in this money market fund so it earns a yield in the meantime. You can leave it there, spend it, transfer it out, or use it to buy securities whenever you’re ready — nothing about SPAXX restricts what you can do with your cash.
Is SPAXX FDIC Insured? (No — Here’s What It Actually Has)
This is the single most common misconception about SPAXX, so it’s worth being precise: SPAXX is not FDIC insured. FDIC insurance only applies to deposits at a bank. SPAXX is a mutual fund — a security you own shares of — not a bank deposit, so it isn’t eligible for FDIC coverage no matter how stable it is.
What SPAXX actually has is SIPC protection, and that’s a different thing:
- SIPC (Securities Investor Protection Corporation) protects you if your brokerage firm fails and your securities or cash go missing — it replaces what’s lost, up to $500,000 in securities (including a $250,000 sub-limit for cash). Fidelity also carries additional excess-of-SIPC coverage beyond that.
- SIPC does not protect against a decline in value. It exists for firm failure, not investment performance. In practice this rarely matters for a government money market fund, since SPAXX is designed to maintain a stable $1.00 share price, but it’s a different guarantee than FDIC deposit insurance.
- FDIC insurance only covers actual bank deposits, and it protects your principal directly, dollar for dollar, up to $250,000 per depositor per bank.
If you specifically want FDIC coverage on your uninvested cash, Fidelity offers that as a separate option: the FDIC-Insured Deposit Sweep Program, which sweeps cash into FDIC-insured deposits at partner banks instead of a money market fund. It’s a different core position you can switch to — SPAXX is simply Fidelity’s default.
How Much Can I Earn With SPAXX?
SPAXX’s yield floats with short-term interest rates and changes regularly — it’s not a fixed rate. As of September 25, 2026, Fidelity’s fund page showed a 7-day yield of 3.46%, with an expense ratio of 0.42% already factored into that figure. Always check the current yield on Fidelity’s SPAXX fund page before doing your own math, since it can move from month to month, especially around Federal Reserve rate decisions.
As a rough example, at a 3.46% yield, $50,000 parked in SPAXX for a full year would earn approximately $1,730, or roughly $144/month — though your actual return depends on the rate at the time and how long the cash stays in the fund.
How the interest is paid: SPAXX accrues dividends daily based on that day’s yield, and Fidelity credits (pays out) those accumulated dividends to your account once a month, on the last business day. The payout is automatically reinvested into more SPAXX shares by default, so your balance compounds over time unless you have dividends set to pay out in cash instead.
Can I Lose Money in SPAXX?
SPAXX is designed to maintain a stable $1.00 per share net asset value, which is the whole point of a government money market fund — it’s built for stability, not growth. Because it holds short-term U.S. government securities and repurchase agreements backed by them, it carries very low credit risk.
That said, a money market fund is still technically a security, not an insured deposit, so it isn’t legally guaranteed against loss the way FDIC-insured cash is. In practice, government money market funds like SPAXX have an extremely strong track record of holding their $1.00 share price, but “extremely low risk” and “zero risk, guaranteed by the government” are two different things — SIPC coverage is a separate matter: it protects customers if a brokerage firm fails, not against a decline in a fund’s value.
SPAXX vs. a Savings Account
SPAXX behaves a lot like a high-yield savings account in daily use — cash is liquid, it earns a competitive yield, and you’re not locked into a term. But there are real differences:
| SPAXX | Bank Savings Account | |
|---|---|---|
| What it is | A government money market mutual fund (a security) | A bank deposit |
| Protection | SIPC (firm failure), not FDIC | FDIC insured up to $250,000/bank |
| Yield | Floats daily with short-term rates | Set by the bank, can be changed anytime |
| Access | Used directly for trades; transfers to an external bank take a few business days | Often has same/next-day transfers, debit access |
Is Parking a Large Balance in SPAXX a Smart Move?
Pros:
- Stability. Government-backed holdings and a stable $1.00 share price make it a low-drama place to hold cash you’re not ready to invest.
- Liquidity. You can use the balance to buy securities instantly, with no waiting period, unlike a CD or bond.
- Competitive yield. Money market yields have tracked short-term rates closely, which has made SPAXX a reasonable place to park an emergency fund or dry powder compared with a typical bank savings rate.
Cons:
- Opportunity cost. Cash sitting in SPAXX for years isn’t invested in the market, so you give up the higher long-run returns stocks and other assets have historically offered.
- Not FDIC insured. If that specific guarantee matters to you, use Fidelity’s FDIC-Insured Deposit Sweep Program instead, or a bank account outside Fidelity.
- Withdrawal timing. Moving money out to an external bank account typically takes a few business days, versus instant debit-card access at most banks.
- Yield isn’t fixed. Unlike a CD, the rate moves with the market — it can go up or down.
Frequently Asked Questions
Is SPAXX a mutual fund or a money market fund?
Both — SPAXX is a money market mutual fund. Money market funds are a specific category of mutual fund designed to preserve a stable share price (typically $1.00) while investing in short-term, high-quality debt.
What’s the difference between SPAXX and SPRXX?
SPAXX (Fidelity Government Money Market Fund) invests almost entirely in U.S. government securities and government-backed repurchase agreements. SPRXX (Fidelity Money Market Fund) is a “prime” fund that also holds commercial paper and certificates of deposit from private issuers, which historically has let it earn a slightly higher yield in exchange for taking on a bit more credit risk. Both charge the same 0.42% expense ratio.
How do I buy or sell SPAXX?
You typically don’t need to “buy” SPAXX manually — it’s your account’s core position, so uninvested cash lands there automatically. To move money out of it, you either use it directly to purchase a security (which sells the needed SPAXX shares automatically) or initiate a withdrawal/transfer from your account to move cash elsewhere.
Is the interest from SPAXX taxable?
Yes, dividends from SPAXX are generally taxable as ordinary income at the federal level (unless held in a tax-advantaged account like an IRA). Because SPAXX holds U.S. government obligations, a portion of its income each year may be exempt from state and local income tax, depending on your state’s rules — Fidelity publishes the exact percentage annually in its tax information for shareholders. Check Fidelity’s tax center or a tax professional for your specific situation.
How often does SPAXX pay interest?
SPAXX accrues dividends daily and pays (credits) them to your account once a month, on the last business day of the month.
Sources: Fidelity, SPAXX fund summary; Fidelity, Account protection (SIPC & FDIC); SIPC, What SIPC Protects. Yield figures as of late September 2026 — check current rates before relying on them. Updated September 2026.
Related guides
- SPAXX vs. FDIC: Risk Comparison
- Is Fidelity FDIC Insured & SIPC Protected in 2023? The Truth!
- Rate Cut Era What happens to SPAXX when Fed cuts rates?
- How Safe Is Fidelity Money Market Fund? Can It Drop Below $1?
Frequently Asked Questions
What is SPAXX at Fidelity?
SPAXX is the Fidelity Government Money Market Fund, the default place where uninvested cash in many Fidelity accounts is held. Fidelity’s fund page lists its objective as seeking as high a level of current income as is consistent with preservation of capital and liquidity.
Is SPAXX FDIC insured?
No. SPAXX is a money market mutual fund, not a bank deposit, so FDIC insurance does not apply. SIPC coverage is separate: it protects customers if a brokerage firm fails, not against a decline in a fund’s value.
What is SPAXX’s current yield?
Fidelity’s fund page showed a 7-day yield of 3.46% as of September 25, 2026. The yield changes with short-term interest rates, so check the fund page for the current figure.
What does SPAXX cost?
Fidelity’s fund page listed a gross expense ratio of 0.42% as of June 29, 2026, and a minimum to invest of $0.00.
Is SPAXX guaranteed to stay at $1.00 per share?
The fund’s net asset value was $1.00 on September 25, 2026, and it is designed to hold a stable price. That is a goal, not a government guarantee.
Related reading: our compound interest calculator, plus the current SPAXX yield compared with FDRXX, SGOV and Treasury bills.
I’m new here. I’m a big fan of Fidelity, but I’m curious about SPAXX. I see that it’s listed as “cash,” but I’m not sure if it’s cash that I can use to invest or if it’s already invested in the market. Can anyone clarify this for me?
This is an interest-bearing money market account that holds your cash until you decide to invest it.
SPAXX and SPRXX keep climbing slowly. It’s the perfect place to park some cash as opposed to CDs, where you have to commit to a timeline.
While my bank offers a 3.75% interest rate on my savings account, I’ve noticed that options like SPAXX yield over 4%. Currently, it is the simplest choice for flexibility.
I looked at the SPAXX information and noticed that the 1 year yield is 1.31%, which is much higher than the local bank’s money market. But then it drops down a bit. At the end of the chart, it shows 2.54% for Life.
This was under the Quarter-End Annual Average End Returns. Although I see 7 Day yield at 4.11%, which is fascinating. Am I to understand that this SPAXX fund will compound/yield/grow over time if I keep some of the money in there even if I don’t invest in other stocks or bonds?
I know it’s not FDIC insured, but it accrues a tiny bit faster than a money market or savings account that a regular bank does, and as long as I keep depositing/contributing to it. Otherwise, it does look like it’s designed for short term than long term investing.