Is SPAXX or FCASH Better? Which is Better SPAXX or FCASH
Fidelity offers SPAXX and FCASH as core position options for holding uninvested cash in eligible accounts.
SPAXX invests in short-term U.S. government securities, while FCASH is an interest-bearing cash balance.
Is SPAXX a Good Investment? See the Pros, Cons & Risks
SPAXX vs. FCASH
The table below compares SPAXX and FCASH based on their current rates, how each option works, liquidity, fees, and other key features. Rates are time-sensitive and can change.
| Feature | SPAXX | FCASH |
|---|---|---|
| What is it? | Government money market fund | Fidelity cash balance |
| How does it work? | Your cash is invested in a money market fund | Your cash stays as a brokerage credit balance |
| Current rate | 3.34% 7-day yield | 1.94% interest rate |
| Can the rate change? | Yes, as market conditions change | Yes, Fidelity can change the rate |
| Main goal | Earn income while keeping cash liquid | Keep cash readily available and earn interest |
| Value | Targets a stable $1 per share | Cash is recorded as a cash balance |
| Liquidity | High | High |
| FDIC insured? | No | No |
| SIPC protection | Generally applicable to eligible brokerage securities | Generally applicable to eligible brokerage assets |
| Expense ratio | 0.42% gross | None because FCASH isn’t a mutual fund |
| Minimum | None when available as a core position | None |
| Best understood as | An investment for your idle cash | Cash sitting in your Fidelity account |
SPAXX is a government money market mutual fund, while FCASH is a Fidelity free credit balance. SPAXX currently has a 3.34% 7-day yield, compared with FCASH’s 1.94% interest rate.
Which Fidelity core position should you choose?
Compare SPAXX, FZFXX, FCASH, and the FDIC sweep to understand yield, taxes, insurance, liquidity, and how each option holds your cash.
Compare Fidelity Core Options
Yield Comparison
SPAXX’s yield substantially exceeds FCASH’s rate.
In mid-2022–2023, SPAXX briefly paid 5%+ when Fed rates were highest; FCASH stayed lower.
SPAXX vs FCASH — Historical Yield Comparison
Annual total return / interest rate, 2019–2026
SPAXX — Current Yield
3.34%
7-day yield as of Sept. 10, 2026
FCASH — Current Rate
1.94%
Interest rate as of Sept. 18, 2026
Bars with no value indicate a year Fidelity has not officially published a historical rate for that fund; hover any bar for the exact figure and its source note. 2026 figures are year-to-date / as of the dates shown.
Safety & Risk Comparison
SPAXX and FCASH both provide access to cash in a Fidelity account, but they differ in how the cash is held and protected.
| Risk | SPAXX | FCASH |
|---|---|---|
| Credit Risk | Very low. Invests mainly in U.S. government securities and government repos. | Different type of risk. It is a Fidelity cash balance, not a money market fund. |
| Value Risk | Targets a $1 share price, but it can theoretically lose value. | No mutual fund NAV to fluctuate because FCASH is a cash balance. |
| Liquidity | Very high. Designed for easy access to your money. | Very high. Available for normal brokerage transactions and withdrawals. |
| FDIC Insured? | No | No |
| SIPC Protection | Yes, subject to SIPC rules and limits | Yes, subject to SIPC rules and limits |
| Simple Explanation | Your cash is invested in a government money market fund. | Your cash is held as a Fidelity brokerage cash balance. |
So, Should You Choose SPAXX or FCash
Choose SPAXX if…
You want the
- Highest cash-like yield and are comfortable with an MM fund’s tiny risks.
- SPAXX typically outperforms FCASH, especially in rising-rate environments.
- It suits investors using Fidelity as a brokerage and wanting to park cash in a fund while earning competitive interest.
But it has no minimum and no transaction fees.
The downside is that SPAXX is not FDIC-insured, but it is extremely safe due to its portfolio.
It can also incur tiny fluctuations or delays in a major crisis.
Choose FCASH if…
- You prioritize absolute simplicity and use of cash within Fidelity.
- FCASH is ideal for very short-term parking with instant access via debit card or withdrawals, and
- it involves effectively no investment risk
- It is also convenient if you want to keep all your cash unsettled.
The trade-off is lower yield: historically, FCASH pays less than money-market funds.
FCASH interest is taxed as ordinary income.
You can use FCASH if yield differences are less important than having pure cash convenience.
When Does SPAXX Pay Interest?
Find out when SPAXX interest accrues, when your dividend is paid, and what happens at the end of each month.
How to Change From FCASH to SPAXX
You can switch your Fidelity brokerage account’s core position from FCASH to SPAXX:
On Fidelity Web:
- Log In to Fidelity.com
- Go to your Accounts > Portfolio/Positions page.
- Find your Core Cash Option (likely listed as FCASH – Taxable Interest Cash Option in Positions).
- Click or select FCASH
- Look for a link/button: Change Core Position
- In the pop-up or new screen, you’ll see alternative core options (e.g., Government MM (SPAXX) and others)
- Select SPAXX
- Review and confirm the change.
This will sweep your future cash balances into SPAXX.
On Fidelity Mobile App:
- Open the Fidelity app and log in.
- Tap Accounts and navigate to Positions
- Tap the FCASH line
- Click Change Core Position
- Choose Fidelity Government Money Market Fund (SPAXX) from the list.
- Confirm the change.
- The app will update your core to SPAXX.
After switching, any new cash will automatically go into SPAXX.
Existing FCASH can be moved by buying SPAXX shares.
SPAXX vs. FCASH FAQ
No. FCASH is a brokerage cash sweep balance, not a bank deposit, and it is not FDIC-insured.
No. SPAXX is a money market fund, not a bank account, and its $1.00 share price is not guaranteed.
SPAXX has historically paid a higher yield than FCASH, but the rates can change over time.
FCASH interest is generally reported on Form 1099-INT, while SPAXX distributions are generally reported on Form 1099-DIV.
Fidelity can sell SPAXX shares to cover eligible cash transactions, including spending with an eligible debit card or checks.
SIPC may protect eligible securities and cash if Fidelity fails, subject to SIPC limits and rules.
Yes. You can have one core position while also holding SPAXX separately as an investment.
SPAXX has an expense ratio, while FCASH does not have a separate fund expense ratio.
FCASH interest is generally accrued daily and credited monthly.
No. Neither generally requires a minimum balance for ordinary retail use.
An FDIC sweep may provide FDIC coverage across participating banks, subject to applicable coverage limits and program rules.
References:
4 Comments