HYSA vs Money Market Funds 2026: Where to Park Cash for the Best Yield
Cash finally pays real money again, but only if it is in the right place. This is the 2026 decision framework for choosing between a high-yield savings account and a money market fund without leaving 100 basis points on the table.
The 30-second version
A high-yield savings account (HYSA) is a bank deposit product: your dollars are FDIC-insured, the rate is set by the bank, and you can transfer money out on any business day. A money market fund (MMF) is a mutual fund holding short-term Treasury bills, commercial paper, or repos: your dollars are held at a broker, SIPC-covered against broker failure, and the yield floats every day with the underlying paper. Both are cash equivalents in 2026, but the small print (taxes, insurance, and same-day settlement) is where the wrong choice quietly costs you real money.
High-Yield Savings (HYSA)
- FDIC-insured up to $250,000 per depositor, per bank, per ownership category
- Rate is bank-set and adjustable (banks often lag the Fed on the way down)
- Interest is 100% taxable at your federal and state ordinary income rate
- ACH transfers usually 1 to 3 business days to a linked bank
- Best for: emergency fund and 0 to 3 month cash you need on demand
Money Market Fund (MMF)
- Not FDIC-insured; SIPC covers the brokerage account, not the yield
- Yield tracks short-term rates like SOFR and 4-week T-bills within days
- Government and Treasury MMFs may skip state income tax on most of the yield
- Same-day settlement in your brokerage account; T+1 to send out to a bank
- Best for: cash inside a brokerage waiting to be deployed into stocks or bonds
2026 yields: where the rates actually stand
After the Fed's cutting cycle through 2024 and 2025, the fed funds range sits in the mid-3s in mid-2026. Government money market funds are tracking that closely because their portfolios reset every few weeks. HYSAs are stickier: the top online banks moved down more slowly than the fund yields, so the two are unusually close right now. Big-brand brick-and-mortar savings accounts are still stuck in the 0.01% to 0.05% range and should be ignored entirely.
| Product | Typical 2026 SEC Yield / APY | Insurance | State tax on interest |
|---|---|---|---|
| Vanguard Federal Money Market (VMFXX) | ~3.7% SEC yield | SIPC (broker) | Partly exempt in most states |
| Fidelity Treasury Only MMF (FDLXX) | ~3.5% SEC yield | SIPC (broker) | Mostly exempt in most states |
| Schwab Value Advantage MMF (SWVXX) | ~3.8% SEC yield | SIPC (broker) | Fully taxable in most states |
| Marcus / Ally / SoFi HYSA (representative) | 3.6% to 4.2% APY | FDIC up to $250k | Fully taxable |
| Big-bank brick-and-mortar savings | 0.01% to 0.05% APY | FDIC up to $250k | Fully taxable |
| 4-week T-bill (bought direct) | ~3.6% yield | US Treasury (full faith) | State tax exempt |
Safety: FDIC vs SIPC vs Treasury-backed
The insurance question is where most beginners overpay for the wrong kind of safety. FDIC insures HYSA balances up to $250,000 per bank per ownership category against the bank failing. SIPC insures a brokerage account against the broker failing, not against a money market fund losing value. And a government or Treasury MMF holds securities backed by the US Treasury, which is a different (and historically stronger) kind of guarantee than SIPC alone.
Tax treatment quietly changes the winner
Interest from both HYSAs and MMFs is taxed as ordinary income at the federal level. The difference shows up on your state return. A Treasury money market fund earns most of its income from federal obligations, and most states exempt federal-obligation interest from state income tax. If you live in California, New York, or another high-tax state, a Treasury MMF yielding 3.5% can beat an HYSA yielding 3.8% on an after-tax basis. Always compare after-tax yields, not headline APYs.
Where each one fits inside a real portfolio
Cash is not a single bucket. Emergency reserves, near-term spending, and dry powder waiting to be deployed all behave differently. The trick is matching the product to the job, not stuffing everything into one account and losing yield on some slice of it.
- Emergency fund (3 to 6 months of expenses): HYSA at an online bank. FDIC-insured, transfers to your checking, and the yield is close enough to a Treasury MMF that the convenience wins.
- Short-term goals (car down payment, tax bill, vacation): HYSA or Treasury MMF, whichever pays more after your state tax rate.
- Dry powder inside a brokerage: Government or Treasury MMF, because it settles same-day and you can flip it into an ETF without waiting for an ACH.
- Cash inside an IRA or 401(k): Whatever your custodian's default sweep fund pays, or a manually purchased government MMF ticker if the sweep pays garbage.
- Long-term portfolio cash allocation: Ladder short T-bills or use SGOV / BIL if you want the state tax exemption in a taxable account.
How to decide in 60 seconds
PICK IN 5 QUESTIONS
- Do you need same-day settlement to buy stocks or ETFs? If yes, use a government or Treasury MMF inside the brokerage.
- Do you need to pay bills from this money via a debit card or ACH transfer? If yes, use an HYSA at a bank that links cleanly to your checking.
- Do you live in a state with 5%+ income tax? If yes, compare after-tax yields. A Treasury MMF often wins there.
- Is the balance over $250,000? If yes, either split across FDIC-insured banks or use a Treasury MMF (no per-account cap).
- Is this money for a goal more than 12 months out? If yes, consider stepping up to a short T-bill ladder or SGOV instead of either option here.
How to actually move the money
For an HYSA, open the account online (Marcus, Ally, SoFi, Wealthfront Cash, and Fidelity Cash Management are the usual suspects in 2026), link your existing checking, and pull money in with an ACH transfer. For a money market fund, log into your brokerage, buy the ticker like any other mutual fund (VMFXX, FDLXX, SWVXX, SPAXX depending on the broker), and you are done. There is no minimum holding period, no early-withdrawal penalty, and settlement is same-day for orders placed before the fund's cutoff (usually 4pm ET).
One workflow note that saves headaches: at Fidelity and Schwab, your account's core sweep position is where uninvested cash automatically lands. On Fidelity, SPAXX is the government MMF default. On Schwab, cash sits in a bank sweep by default (paying almost nothing), and you have to manually buy SWVXX to get the yield. Check your account's cash settings today; a lot of Schwab customers accidentally leave five figures earning 0.45%.
Cash allocation and portfolio drift
Whichever product you pick, the balance itself is a portfolio allocation. If your target is 5% cash and it drifts to 12% because you keep parking dividends there, you are underweight equities by 7% and dragging returns. This is exactly the kind of thing Wealth Rebalancer flags for you against your target weights, so cash stops silently ballooning while you were busy chasing 20 basis points of yield.
Frequently asked questions
Is a money market fund safer than a high-yield savings account?
Neither is objectively safer, they carry different risks. An FDIC-insured HYSA is protected against the bank failing, up to $250,000 per depositor. A Treasury or government money market fund holds US Treasury securities, which are considered the world's benchmark for creditworthiness but are not FDIC insured. For balances under $250,000 in a stable bank, an HYSA is the simpler safety story. For very large balances or investors already inside a brokerage, a Treasury MMF is often the more scalable option.
Can a money market fund lose money?
In theory yes, in practice this is rare. Two prime money market funds have broken the buck (fallen below $1.00 NAV) in stress events: the Reserve Primary Fund in 2008, and several prime funds required fee waivers and briefly imposed liquidity gates in 2020. Government and Treasury money market funds have never broken the buck. If capital preservation is your first priority, choose a government or Treasury fund, not a prime fund.
What is the difference between SPAXX, VMFXX, SWVXX, and FDLXX?
SPAXX is Fidelity's core government money market fund and is often the default cash sweep. VMFXX is Vanguard's federal money market fund, holding mostly Treasury bills and repos. SWVXX is Schwab's prime money market fund (higher yield, slightly more risk, held commercial paper). FDLXX is Fidelity's Treasury-only fund, which is best for maximizing the state tax exemption on Treasury interest. All are $1.00-per-share money market funds under Rule 2a-7.
Do I owe state income tax on money market fund interest?
It depends on what the fund holds. Interest from Treasury securities is exempt from state and local income tax under federal law, so a Treasury money market fund passes that exemption through to shareholders on the portion of its income earned from Treasuries. Prime money market funds hold commercial paper and CDs, which are fully state-taxable. Your fund's annual tax document will show the exempt percentage.
How much of my portfolio should sit in cash?
For long-term investors, most target 0% to 10% of the portfolio in cash, with a separate emergency fund held outside the investment account. Higher cash allocations create meaningful drag over multi-decade horizons because equity risk premiums historically outpace short-rate yields by a wide margin. If you are drifting above your target because dividends and contributions keep landing there, that is a rebalancing signal.
Where should I keep my emergency fund in 2026?
A high-yield online savings account is the standard answer because it keeps emergency money outside your brokerage (removing the temptation to invest it), gives you FDIC protection up to $250,000, and delivers a competitive rate. If you already keep an emergency fund in a brokerage, a Treasury money market fund is fine, but be aware there is no debit card and ACH transfers still take a business day or two.