# Money Market Funds for Corporate Treasury

Source: https://gravam.com/blog/money-market-funds-for-corporate-treasury
Author: Tan Gravam
Published: 2026-07-24
Updated: 2026-10-04
Reviewed: 2026-10-04
Summary: Money market funds pool short-dated, high-quality instruments to give treasury same-day liquidity and a yield on cash — inside policy, not chasing return.

**A money market fund pools your cash with everyone else's into a diversified portfolio of short-dated, high-quality instruments, and gives you back same-day or next-day liquidity plus a modest yield.** For corporate treasury it is one of the most common homes for operating and reserve cash — a rated, transparent, professionally managed vehicle that sits neatly inside the security-then-liquidity-then-yield discipline. It earns its place not by paying the most, but by preserving capital and staying liquid while it does. Reach for it the other way round and it will teach you the difference the hard way.

_(This is general education on how corporate treasury uses these funds, not investment advice — the point is the treasury lens, not a recommendation for any specific situation.)_

## How to choose a money market fund for corporate treasury

There is no "best" money market fund for corporate treasury, and this site does not name funds. That is not coyness: the right fund depends on your currency, your jurisdiction, your investment policy and the day's cut-off times, and a list of names would be stale the moment a fund's portfolio or rating changed. What can be stated — and checked — is the set of criteria a treasury uses to choose one:

1. **Fund type and NAV behaviour.** In the EU, is it a public debt CNAV, an LVNAV or a VNAV fund, and is it short-term or standard? In the US, is it a government fund with a stable share price or an institutional prime fund with a floating NAV? The type decides what the fund may hold and whether the price you redeem at can move. The categories are defined in law — see [what the rules say](https://gravam.com/blog/money-market-funds-for-corporate-treasury#what-the-rules-actually-say) below.
2. **Credit quality.** What the fund holds, and whether it carries a money-market fund rating that meets your policy's floor. A rating is a starting point, not a substitute for looking at the holdings.
3. **Maturity limits: WAM and WAL.** Weighted average maturity measures interest-rate sensitivity; weighted average life measures how long the credit is really outstanding. Both the EU regulation and the SEC's rule cap them at 60 and 120 days for the short-term fund types. A standard EU fund is allowed up to 6 and 12 months, which makes it a different instrument.
4. **Liquidity terms.** Same-day or next-day settlement, the dealing cut-off time in your time zone, and the fund's daily and weekly liquid-asset levels against the regulatory minimums. Also read what the fund may do in stress — liquidity fees, and in the EU redemption gates or suspension.
5. **Fund size and your share of it.** A holding that is a large fraction of a fund makes you part of its liquidity problem. A policy can cap the treasury's position as a percentage of the fund's assets; the right percentage is a policy choice, not a regulatory number.
6. **Currency.** The fund should be in the currency the cash is needed in. A fund in another currency adds an FX position to what was meant to be a cash holding.
7. **Policy and counterparty limits.** Is the fund type on the investment policy's permitted list, and does the look-through exposure to the underlying issuers — often the same banks you already hold deposits with — stay inside your [counterparty limits](https://gravam.com/blog/managing-surplus-cash)?

A fund that passes all seven is a candidate. Yield is what you compare _between_ candidates, never the reason one becomes a candidate.

## What a money market fund actually is

Start from the [short-term investment basics](https://gravam.com/blog/managing-surplus-cash): once you have surplus cash and a policy, you need somewhere to put it. A money market fund (MMF) is one option — a collective fund that invests in the money markets, meaning very short-dated, high-quality instruments: government paper like Treasury bills, repurchase agreements (repo), commercial paper (CP), and certificates of deposit (CDs). You buy units in the fund rather than the underlying paper directly, and in return you get diversification, professional management, and typically same-day or next-day access to your money.

The appeal for treasury is that it does three jobs at once. It puts idle cash to work at a yield. It keeps that cash liquid. And it spreads the underlying credit across many issuers instead of parking it all with a single bank. For a treasurer whose real job is preserving operating cash rather than growing it, that combination is exactly the right shape.

## The main types

Not all MMFs sit in the same place on the risk spectrum, and the distinction matters more than the marketing sometimes suggests.

- **Government / treasury funds** hold government paper and government-backed repo. This is the lower-risk end: the underlying credit is about as good as short-term paper gets, and the yield reflects that. When capital preservation is the whole point, this is usually where it starts.
- **Prime funds** can also hold high-grade corporate instruments — CP and CDs from banks and companies. That broader universe typically pays a little more, but "a little more yield" is never free: it comes from taking a little more credit and liquidity sensitivity. In the US there are also **municipal** funds that hold short-dated municipal paper, relevant mainly for their tax treatment.

Cutting across those categories is the **NAV** distinction. Some funds aim to hold a stable, constant net asset value (CNAV) — a unit is worth what you paid, and you think of it like cash. Others carry a variable NAV (VNAV) that moves, however slightly, with the value of the underlying holdings. The stable-NAV label is convenient, but it is worth remembering it is an accounting and structural feature, not a guarantee that value can never move.

## What the rules actually say

"Government versus prime" and "CNAV versus VNAV" are market shorthand. The legal categories are narrower, and they differ between the EU and the US.

**In the EU**, the rulebook is [Regulation (EU) 2017/1131](https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32017R1131) on money market funds, dated 14 June 2017 and applying from 21 July 2018 (Article 47). Article 3 allows exactly three types:

- **Public debt CNAV MMF** — seeks an unchanging NAV and must invest at least 99.5% of its assets in the public debt instruments listed in Article 17(7), reverse repo secured with government debt, and cash.
- **LVNAV MMF** (low-volatility NAV) — may deal at a constant NAV only while that constant NAV stays within 20 basis points of the mark-to-market NAV. Beyond that, the next redemption or subscription is at the mark-to-market NAV (Article 33).
- **VNAV MMF** — deals at a variable NAV.

Separately, a fund is either **short-term** or **standard**. A short-term MMF must keep WAM at no more than 60 days and WAL at no more than 120 days (Article 24). A standard MMF may run WAM up to 6 months and WAL up to 12 months (Article 25), and a standard MMF cannot be a public debt CNAV or an LVNAV fund — so every constant-NAV fund in the EU is a short-term fund.

The same articles set liquidity floors: LVNAV and public debt CNAV funds must hold at least 10% of assets in daily maturing assets and 30% in weekly maturing assets; VNAV funds, 7.5% and 15%. Diversification is written in too: as a general rule no more than 5% of assets in money market instruments from one issuer and no more than 10% in deposits with one bank, with derogations set out in Article 17.

Fees and gates apply to public debt CNAV and LVNAV funds (Article 34). If weekly maturing assets fall below 30% _and_ net redemptions on one day exceed 10% of assets, the fund's board must assess the situation and may apply liquidity fees, gate redemptions to 10% of units a day for up to 15 working days, suspend redemptions for up to 15 working days — or take no immediate action. If weekly maturing assets fall below 10%, the board must apply liquidity fees or a suspension. And Article 35 prohibits external support: a sponsor may not step in to prop up the NAV.

**In the US**, money market funds are governed by the SEC's rule 2a-7. Two things matter for a corporate investor:

- **Who floats.** Government and retail funds may sell and redeem at a stable share price, typically $1.00. Institutional prime and institutional tax-exempt funds must use a floating NAV, rounded to the fourth decimal place — a requirement that dates from the SEC's 2014 reforms. A corporate treasury is an institutional investor, so its stable-price option in the US is a government fund.
- **The 2023 amendments.** The SEC adopted [further reforms](https://www.sec.gov/files/rules/final/2023/33-11211.pdf) on 12 July 2023, with the rule amendments effective 2 October 2023. They removed a fund's ability to suspend redemptions through a gate and cut the link between liquidity thresholds and liquidity fees. They raised the minimum daily and weekly liquid assets to 25% and 50% (from 10% and 30%). And they require institutional prime and institutional tax-exempt funds to charge a liquidity fee when daily net redemptions exceed 5% of net assets, unless the fund's liquidity costs are de minimis; that requirement had a compliance date twelve months after the effective date. Any non-government fund may also impose a discretionary fee, capped at 2% of the value redeemed, if its board decides that is in the fund's best interest. WAM and WAL stay capped at 60 and 120 days.

So the two regimes now point in different directions on one tool: the EU regulation as published still provides for gates and suspension on constant-NAV funds, while the SEC has removed gates from rule 2a-7. That is the kind of detail a policy written for "money market funds" in general will miss.

What is not verified here: amendments to the EU regulation after its original publication, the UK's own regime, and the rating agencies' criteria for money-market fund ratings. Read the current consolidated text and the fund's prospectus before relying on any threshold above.

## Why treasury reaches for them

Set MMFs against the alternative — leaving large balances sitting in bank deposits — and the case is straightforward:

- **Diversification away from bank concentration.** A big operating balance in one bank is a single point of failure. An MMF spreads the same cash across many high-grade issuers, which is the same instinct behind [counterparty and concentration limits](https://gravam.com/blog/managing-surplus-cash) applied through a single instrument.
- **Same-day or next-day liquidity.** Used well, the cash is still there when the business needs it — which is the entire second priority of corporate cash investment.
- **Professional management and transparency.** Someone whose full-time job is the money markets manages the portfolio, and a rated fund publishes what it holds. You are not stock-picking short-term paper yourself.
- **A rated vehicle.** MMFs are typically highly rated (top money-market ratings such as the AAA-equivalent scales the agencies use), which gives policy a clean, checkable line to write against.

> A money market fund lets you optimise two of yield, safety and liquidity — never all three. Decide which two the cash needs before you decide which fund it goes into.

That triangle is the honest frame. Every MMF is a specific answer to it, and the answer that pays the most is, by construction, giving something up on one of the other two.

## The treasury lens: it lives inside the policy

None of this is a licence to hunt for the best-yielding fund. MMF use belongs _inside_ the [investment policy](https://gravam.com/blog/managing-surplus-cash), not alongside it. The policy should name which funds are permitted, set a rating floor, and cap concentration — both per fund and, looking through the fund, per underlying issuer — so that "diversification" doesn't quietly recreate a concentration you can't see. This is the same governance that runs through [debt and investment management](https://gravam.com/blog/debt-and-investment-management-in-treasury): the instrument changes, the discipline doesn't.

The reason the order is fixed is the reason it is always fixed for operating cash. You are investing money the business needs to run — payroll, suppliers, debt service. So the point of putting it in an MMF is capital preservation and liquidity **first**, and yield **last**, as the bonus you take only after the first two are satisfied. A fund that pays more but can't be redeemed on the day you need it has failed at the only two things that actually mattered.

## The risk reality

Here is the part the fact sheet underplays: "cash-like" is not "cash." A money market fund is an investment. It is a very conservative, highly rated, short-dated investment — but it is not a guaranteed deposit, and it can face stress. Funds have, in the past, come under real pressure when the short-term markets they invest in seized up. The 2008 experience is the reference point, and the regulatory reforms that followed — the SEC's reforms in the US, the Money Market Fund Regulation in the EU — exist precisely because that risk turned out to be real when it had been treated as theoretical. March 2020 made the point again: the SEC's 2023 release cites the outflows of that month as the reason it rewrote the fee-and-gate framework. The thresholds are set out [above](https://gravam.com/blog/money-market-funds-for-corporate-treasury#what-the-rules-actually-say); the point that matters for a treasurer is simpler: the rules keep being revised, which tells you the risk was never zero.

Which leads to the one habit worth building: **read what the fund actually holds.** Government or prime? What's the maturity profile? Who are the underlying issuers, and does the fund's concentration blow through the limits your own policy sets? A fund is not a black box you rate once and forget; it's a portfolio you can look through, and looking through it is the difference between managing the risk and hoping it isn't there. This is where MMFs connect to broader [liquidity risk management](https://gravam.com/blog/liquidity-risk-management): the fund is only as liquid as the paper inside it on the day everyone wants out at once.

## The yield trap in money market funds

On paper, MMFs are the easy button — cash-like, highly rated, liquid, done. In reality, the trap is dependably the same one. A treasurer under pressure to make the cash earn more reaches for the highest-yielding fund on the list, ticks the "AAA-rated" box, and moves on. Then a stress event arrives and the yield reveals its source: it was compensation for credit and liquidity risk that never showed up in calm markets and was never priced when the fund was chosen.

The lesson isn't to avoid MMFs — they're a genuinely good tool, and I've relied on them for a long time. The lesson is to remember what job they're doing. Preservation and liquidity are the mandate; yield is what you're allowed to keep once the mandate is met. Track it like the rest of treasury: the [KPIs that measure treasury performance](https://gravam.com/blog/treasury-kpis-measuring-treasury-performance) should reward safe, liquid, well-diversified cash, not the last few basis points squeezed out of it. Choose the fund that does the job, know what it holds, keep it inside the policy — and an MMF becomes exactly what it should be: a quiet, dependable home for cash, not a bet you didn't know you were making.

***

_See also [managing surplus cash](https://gravam.com/blog/managing-surplus-cash) and [liquidity risk management](https://gravam.com/blog/liquidity-risk-management)._

## Primary sources

EU rules read from Regulation (EU) 2017/1131 as published in the Official Journal (Articles 2, 3, 10, 17, 24, 25, 33, 34, 35 and 47); later amendments and the consolidated text were not re-read, and the UK's post-Brexit regime is not covered. US rules read from the SEC's July 2023 adopting release (33-11211) and its press release. Rating-agency criteria and any individual fund's dealing cut-off times are not verified here — check the prospectus.

- EUR-Lex — Regulation (EU) 2017/1131 of the European Parliament and of the Council of 14 June 2017 on money market funds — accessed 2026-10-04 — https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32017R1131
- SEC — Money Market Fund Reforms; Form PF Reporting Requirements for Large Liquidity Fund Advisers (Release No. 33-11211, final rule) — accessed 2026-10-04 — https://www.sec.gov/files/rules/final/2023/33-11211.pdf
- SEC — Press release 2023-129: SEC Adopts Money Market Fund Reforms and Amendments to Form PF Reporting Requirements for Large Liquidity Fund Advisers (12 July 2023) — accessed 2026-10-04 — https://www.sec.gov/newsroom/press-releases/2023-129

## Questions this article answers

**Q: What are the best money market funds for corporate treasury?**

There is no single best money market fund for corporate treasury, and naming one would be a product recommendation that goes stale as soon as a portfolio or rating changes. Treasuries choose by criteria instead: the fund type and how its NAV behaves (in the EU, public debt CNAV, LVNAV or VNAV under Regulation (EU) 2017/1131; in the US, a stable-price government fund or a floating-NAV institutional prime fund under SEC rule 2a-7), the credit quality of the holdings and the fund's rating, its weighted average maturity and weighted average life (capped at 60 and 120 days for EU short-term funds and US funds), its liquidity terms and dealing cut-off, the fund's size relative to your holding, its currency, and whether it fits the investment policy's counterparty and concentration limits.

**Q: What is a money market fund?**

A money market fund is a pooled investment fund that holds a diversified portfolio of short-dated, high-quality money-market instruments — typically government paper such as Treasury bills, repurchase agreements, commercial paper and certificates of deposit. It aims to preserve capital and offer same-day or next-day liquidity while paying a yield on cash, which makes it a common home for corporate operating and reserve balances. It is not a bank deposit and is not guaranteed.

**Q: What is the difference between a government and a prime money market fund?**

A government (or treasury) money market fund holds government paper and government-backed repurchase agreements, which sits at the lower-risk end of the spectrum. A prime fund can also hold high-grade corporate instruments such as commercial paper and certificates of deposit, which typically offers a little more yield in exchange for a little more credit and liquidity sensitivity. The choice is a trade-off along the yield-versus-safety-versus-liquidity triangle, and which is appropriate depends on the treasury's investment policy.

**Q: Are money market funds safe for corporate cash?**

Money market funds are designed to be low-risk and are typically highly rated, but 'cash-like' is not the same as cash — they are investments, not guaranteed deposits, and they can face stress. The rules written after 2008 — the EU's Regulation (EU) 2017/1131 on money market funds and the SEC's reforms to rule 2a-7, most recently amended in July 2023 — exist precisely because that risk is real if it is underestimated. Used inside a proper investment policy — permitted funds, rating floors, concentration limits — and with attention to what a fund actually holds, they are a well-established tool for preserving and mobilising corporate cash.