Two products, nearly identical names, and one difference that matters more than everything else combined: a money market account at a bank is a federally insured deposit, while a money market fund at a brokerage is an uninsured investment. Plenty of careful savers hold one while believing they hold the other, and the confusion is understandable, since both hold cash-like assets, both pay yields that move with short-term interest rates, and both are pitched as safe places to park money.
The distinction rarely matters on a calm Tuesday. It matters enormously in a financial storm, at tax time, and whenever you are comparing yields that look suspiciously different. Here is how to tell the two apart and decide which one your cash actually belongs in.
The money market account: a bank deposit with a fancier name
A money market deposit account, the kind a bank or credit union offers, is legally a savings deposit. It typically pays a somewhat higher rate than a basic savings account, may come with limited check-writing or debit access, and often requires a higher minimum balance. Most importantly, it sits inside the federal safety net: deposits are insured up to $250,000 per depositor, per institution, per ownership category, by the FDIC at banks and by the NCUA at federally insured credit unions. If the institution fails, the insurance pays. The rate can change at the bank’s discretion, and the account’s fees and yield must be disclosed to you under the Truth in Savings rules, so the fee schedule is worth a read like any other deposit account.
The money market fund: a mutual fund in cash clothing
A money market mutual fund is a type of mutual fund regulated by the Securities and Exchange Commission. It pools investors’ money into short-term, high-quality debt: Treasury bills, government-backed paper, and, in some varieties, short-term corporate IOUs. The SEC’s investor education site is blunt about the key point: a money market fund is not guaranteed by the FDIC, and although these funds aim to hold their value steady, there is a risk of losing money. Historically the risk has been low, and funds holding only government securities are the most conservative of the bunch, but low risk is not the same thing as insured.
Money market funds come in flavors that matter: government funds, prime funds that hold corporate debt for a bit more yield, and municipal funds whose income is exempt from federal income tax, which can make them attractive in higher tax brackets. Each fund’s prospectus spells out what it holds and what it charges, and the expense ratio comes straight out of your yield.
Where each one wins
The deposit account wins on certainty. Money you absolutely cannot afford to see fluctuate, an emergency fund, a house closing next month, a retiree’s spending cushion, has a strong claim to insured status. It also wins on simplicity: one institution, one insured balance, no prospectus.
The fund often wins on yield, especially when short-term rates are high, because funds pass through market rates quickly while banks can be slow to raise deposit rates. It also wins on convenience inside a brokerage account, where a money market fund is typically the default parking spot for cash between investments, and on taxes for investors who benefit from Treasury-only or municipal funds. The SEC’s bulletin on cash sweep programs is worth a look if your broker holds your idle cash, since sweep destinations vary between insured bank deposits and money market funds, and the yield difference between a broker’s default sweep and its best available option can be substantial.
Three checks before you park the cash
First, identify what you actually own. The name will not always tell you; the paperwork will. A deposit account shows FDIC or NCUA membership and appears on a bank statement. A fund has a ticker, a prospectus, and a yield quoted as a seven-day yield.
Second, compare after-fee, after-tax yield. A fund’s advertised yield is net of expenses, but sweep accounts and bank promotions complicate comparisons, so line the numbers up on the same basis before deciding a difference is real.
Third, match the vehicle to the money’s job. Insured deposits for money that must not flinch, funds for cash that can accept a sliver of risk in exchange for market yield. Plenty of households sensibly use both, an insured money market account for the emergency fund and a money market fund for idle brokerage cash, and there is nothing inconsistent about that split; each dollar is simply sitting where its job description says it should. The mistake is not choosing one or the other. The mistake is not knowing which one you chose, and finding out the difference from a headline instead of from your own paperwork.
