The real alternative

Money market funds vs stablecoin yield

An honest comparison of yield, liquidity and risk, including the cases where a money market fund is the better answer.

Rate grid as of September 2026 · USD or USDC · KYB required

The short version

  • A money market fund is the right benchmark for this product — not a checking account — and for most of your cash it stays the right answer.
  • Compare net against net: a fund quotes the 7-day yield of one share class, after that class’s expenses and before tax.
  • Coinstancy Pro pays 6.00% with no lock and up to 6.75% at twelve months, with withdrawals available within 48 hours.
  • The fund settles same day or T+1, and carries a regulated wrapper we do not replicate. This product is not FDIC insured.
  • Decide per bucket of cash, not per product. Most treasuries end up on more than one row of the decision table.
6.00%
APY with no lock-up, withdrawals available within 48 hours
The instrument

How a money market fund works.

This is the instrument a finance director actually compares us against — not a checking account. It is a good product, and knowing exactly what it does is the only way to judge whether anything should sit beside it.

Short-dated, high-quality paper: Treasury bills, repurchase agreements collateralised by government securities, agency discount notes, and — in prime funds — bank certificates of deposit and commercial paper. Weighted average maturity is measured in weeks, not years.

The fund passes through what those instruments pay, minus its expense ratio. There is no leverage and no promotional subsidy. When the short end of the curve moves, the fund’s yield follows it within weeks.

Government and retail funds are managed to a stable $1.00 net asset value. Institutional prime and municipal funds carry a floating NAV and, under the SEC’s 2a-7 rules, can apply a mandatory liquidity fee when daily net redemptions cross a threshold.

A registered fund, a prospectus, an independent custodian, an auditor, daily portfolio disclosure and a regulator. That wrapper is a real part of what you are buying, and it is the part we do not replicate.

Money market fund. A registered fund holding short-dated paper. Not a deposit, not FDIC insured. The yield floats daily.

Money market account. A bank deposit product with a rate the bank sets, FDIC insured up to the limit. Different animal, usually a lower rate.

T-bills held direct. A direct obligation of the US Treasury with a fixed maturity. No fund fee, no fund manager, and no daily liquidity unless you sell.

The current numbers bank by bank sit on the money market rates guide, and the sweep mechanics on the sweep accounts guide.

The number that matters

Net yield after fees in 2026.

Compare net against net. A fund’s headline 7-day yield is net of that share class’s expenses, and the share class you were defaulted into is rarely the cheapest one on the same portfolio.

Getting to the fund’s real number

Gross portfolio yield

What the underlying bills, repo and paper actually earn.

Minus the expense ratio

Deducted daily. The published 7-day SEC yield is already net of it — but it is net of that share class’s expenses only.

Minus the share class spread

Institutional share classes charge less and require higher minimums. A brokerage default sweep class is usually the most expensive one available on the same portfolio.

Then tax

Income from direct Treasury obligations is generally exempt from state income tax; repo and prime paper is not. In a high-tax state that changes the ranking. Ask your accountant, not us.

The Coinstancy Pro side

Introductory rate First six months
7.00% APY
Locked tier, twelve months A locked tier fixes the rate for its term; a fund’s yield floats with the short end
6.75% APY
No lock-up Withdrawals available within 48 hours
6.00% APY
Your money market fund, net of fees The 7-day yield of the share class you actually hold, after its expense ratio and before tax
Your share class

Not guaranteed, not FDIC insured, and the yield is not a deposit rate. Grid as of September 2026. It is refreshed monthly against published bank and fund rates on the rates page, with sources.

The gap, illustrated at two points

Allocated balance
$250,000
Extra per year
+5,000 $
Allocated balance
$500,000
Extra per year
+10,000 $
Allocated balance
$1,000,000
Extra per year
+20,000 $

Illustration only, not a quoted comparison. It assumes a two-point difference — a money market fund net yield in the region of 4% against the 6% no-lock tier — held for a full year, before tax. Neither leg is a sourced figure: fund yields float daily and your own share class is the one that counts. Run your real numbers through the calculator.

Access to the cash

Liquidity compared: T+1 against 48 hours.

The honest summary: the fund is faster and more predictable. The question is whether the difference matters for the specific slice of cash you are placing.

Dimension Money market fund T-bills held direct Coinstancy Pro
Normal redemption Same day if you hit the cut-off, otherwise T+1 At maturity, or same-day sale on the secondary market Available within 48 hours
Cost of leaving early None in normal conditions Market price on sale — you can realise a loss if rates rose No-lock tier: none. Locked tier: capital returned, accrued interest forfeited
Penalty on principal None None if held to maturity None
Conditions attached Institutional prime and municipal funds can apply a mandatory liquidity fee under 2a-7 Secondary market pricing and settlement 48-hour window; onward bank settlement follows your own bank’s timetable
Predictability High and well documented Highest — the maturity date is fixed A window, not an instant transfer

What 48 hours actually means

It is a window during which the withdrawal is made available, not a same-day transfer. On a locked tier, exiting early returns your capital in full and forfeits the accrued interest; there is no penalty on the principal. Onward settlement to your bank then runs on your bank’s own timetable. Plan around the window rather than against it — the mechanism page sets out each step.

Fund liquidity is not unconditional either

Worth stating for completeness rather than as a point against the fund: institutional prime and municipal money market funds can apply a mandatory liquidity fee when daily net redemptions exceed the regulatory threshold. Government funds are the ones people mean when they say a money market fund is always liquid — and for them, in practice, it is.

Risk, honestly

The nature of the risk: counterparty against smart contract.

These are not the same risk at different sizes. They are different shapes. A fund’s risk is diversified across many issuers and shows up as small deviations; a protocol failure is closer to binary and can correlate across positions. Size the allocation to the shape, not to the yield.

The fund’s risks

counterparty and credit
Credit risk on the issuers held — small, diversified, disclosed daily
A break of the $1.00 NAV: rare, but it has happened (Reserve Primary Fund, 2008)
Liquidity fees or restrictions on institutional prime and municipal funds under stress
Sponsor support is discretionary, not contractual

Our risks

protocol and code
Smart contract code bugs and errors — covered through OpenCover
Oracle manipulation or failure, liquidation failure, malicious governance takeover — covered
Depeg of the underlying stablecoin — not covered
Yield below the advertised rate, and anything the policy excludes — not covered

Coverage runs through OpenCover, up to 100% of USD value, subject to policy terms, limits and exclusions. Full scope on the coverage page; the protocol selection criteria are on the protocols page.

What the fund gives you that we do not

FDIC insurance — this product has none
SIPC coverage — this is not a brokerage account
A prospectus, a registered fund and daily portfolio disclosure
A regulator whose mandate is to protect you specifically

Coverage through a policy is a narrower promise than a regulated fund structure, and we would rather say so here than have it surface in your risk committee.

Decide by bucket

The decision table.

The question is never “fund or stablecoin”. It is which bucket of cash you are placing, and what constraint binds first. Find your row.

Your situation Where the cash belongs Why
Cash needed for payroll, payables or a draw inside 30 days Money market fund Same-day or T+1 settlement, and two points of yield over one month is not worth a settlement window you might miss.
A known outflow on a known date — tax, earn-out, acquisition instalment T-bill maturing before that date The maturity matches the liability. No reinvestment risk, no timing judgement to make.
Treasury policy restricts eligible instruments to rated or regulated vehicles Money market fund There is nothing to argue about. Change the policy first if you want to, but do not work around it.
Reserve you have not touched in a year, timing genuinely uncertain No-lock tier at 6.00% Withdrawals available within 48 hours, no forfeiture, and the gap compounds while the cash waits.
Reserve ring-fenced for a quarter or more, with a board that has signed off Locked tier, 6.25% to 6.75% The term fixes the rate. Early exit returns capital and forfeits accrued interest — the trade you are accepting.
You already hold USDC and it is sitting idle in a wallet Coinstancy Pro No conversion, no FX, and coverage on protocol events you almost certainly do not have today.
No eligible entity, or KYB cannot be completed Money market fund KYB is required before the first deposit. Without it there is no account to open.
Balance above insured limits sitting in an operating bank account Move it out first, then decide Concentration at one bank is the risk to fix on day one. A money market fund or an insured cash sweep does that. Allocating a slice is the second decision, not the first.

Most treasuries end up on more than one row. Operating cash and the near-term buffer stay in the fund; only the reserve that has genuinely sat still gets allocated. That split is the intended use — see the bank comparison and the sweep setup.

Where we lose

The cases where the money market fund wins.

Six situations where the fund is the better answer and we are not. If one of them describes your cash, stay where you are — there is no version of this page that argues otherwise.

Our withdrawal window is 48 hours, and that is a window, not a button. If the cash might be needed the same afternoon, the fund is simply the right instrument and we are not.

Two points on $50,000 is roughly $1,000 a year before tax, on the same illustration used above. That does not pay for a KYB file, a policy amendment and a new counterparty in your controls.

A money market fund generally qualifies as a cash equivalent on the balance sheet. A stablecoin position generally does not, and your auditor makes that call, not us. If the classification matters to a covenant or a reporting line, the fund wins outright.

A prospectus, a custodian, an auditor, daily holdings disclosure and a regulator with jurisdiction. Those are real protections. We are covered through OpenCover for specific protocol events — a narrower thing, and it is not a substitute.

Depeg of the underlying stablecoin is not a covered event. If your policy treats that exposure as unacceptable — a defensible position — then no amount of yield resolves it.

When the short end pays well, the gap narrows and the case for taking additional risk gets weaker on its own terms. That arithmetic runs against us and we would rather you check it than take our word for it.

And where we think we are worth a slice

One case, stated as narrowly as we can defend it: a reserve you have not touched for two or more quarters, held by an entity that can complete a KYB, under a treasury policy that permits a defined non-bank allocation with a cap. For that slice, 6.00% with no lock or up to 6.75% at twelve months, with coverage through OpenCover on protocol events, is a trade worth putting in front of a board. Everything else in your treasury should probably stay in the fund.

Request access, or ask the hard questions first.

Open an account directly. If your finance team needs the coverage terms and the KYB requirements before that, a call is the faster route.