How Does a Sweep Yield Compare to a Money Market Fund Yield?
Two options can sit inside the exact same brokerage account and pay noticeably different rates on cash that isn’t otherwise invested. Understanding why starts with seeing what each option actually is.
The short answer
A sweep yield is what a brokerage pays on cash that’s automatically parked in a bank deposit or fund behind the scenes inside a brokerage account, while a money market fund yield is what an investor earns by actively choosing to buy a specific fund with that cash. Sweep yields are generally set with convenience and liquidity in mind and often run lower, while a directly purchased money market fund typically passes along more of what it earns, minus its own expense ratio.
What each option actually is
A sweep vehicle is the default landing spot for uninvested cash inside a brokerage account — it might be a linked bank deposit program or an internally managed cash fund, and it requires no action to use. A money market fund, by contrast, is a specific investment a person chooses to buy, much like any other fund inside the account. It holds short-term, relatively stable instruments and reports a yield that reflects both the underlying holdings and the fund’s own costs, summarized in its expense ratio.
Where the yield gap comes from
The difference often comes down to structure rather than one option being inherently better. A sweep program may involve the brokerage or a partner bank earning a spread — the difference between what it earns on the swept cash and what it pays the account holder. A money market fund operates differently: it pools investor money, invests it in short-term instruments, and distributes nearly all of the return back to fund holders after subtracting its expense ratio. Because the fund structure has less built-in spread for the brokerage to retain, the disclosed yield can end up meaningfully higher, though this pattern doesn’t necessarily hold at every point in time or with every provider.
It’s also worth noting that both yields move together in a general sense, since both are ultimately tied to the same broader interest rate environment. When rates rise or fall across the economy, both the sweep rate and a money market fund’s yield tend to shift in the same direction — the gap between them narrows or widens, but rarely reverses entirely on its own.
Liquidity trade-offs to consider
- Settlement delay. Buying into a money market fund typically takes a business day to settle, whereas sweep cash is generally available the same day.
- Minimums. Some money market funds carry a minimum purchase amount, while sweep cash usually has no minimum.
- Rate visibility. A fund’s yield is usually published and updated regularly, while a sweep rate may be disclosed less prominently and change without much notice.
- Automatic versus manual. Sweep cash requires no ongoing attention; a money market fund position needs to be actively bought, and later sold, when cash is needed elsewhere.
What to weigh
Choosing between the two isn’t just about chasing the higher published number. For cash that might be needed within a day or two — say, to cover an upcoming trade — the built-in convenience of a sweep can outweigh a modest yield difference. For cash set aside for a longer stretch, the gap between a sweep yield and a money market fund yield can add up, making the small settlement delay a worthwhile trade-off. Rates on both options move with broader interest rate conditions, so any comparison made today is only a snapshot, not a fixed feature of either option. Checking both figures side by side in the account’s own disclosures, rather than relying on general assumptions about which one is better, is the most reliable way to know where the account actually stands.