SEC Rule 2a-7 Reform 2010: Tightening Money Market Fund Liquidity Rules

The collapse of the $62.5 billion Reserve Primary Fund in September 2008—triggered by exposure to Lehman Brothers commercial paper—broke the foundational assumption that money market funds were risk-free. In response, the SEC tightened Rule 2a-7 in 2010, imposing stricter maturity ceilings, weighted-average maturity caps, and liquidity floors that persist today.

The Reserve Fund Collapse: Why It Mattered

On September 15, 2008, Lehman Brothers filed for bankruptcy, becoming the largest investment bank failure in U.S. history. The Reserve Primary Fund—one of the largest money market funds in the country—held $785 million in Lehman commercial paper, roughly 1.25% of its $62.5 billion in assets. Within days, the fund disclosed its net asset value (NAV) had fallen below $1.00 per share, a phenomenon known as “breaking the buck.”

Breaking the buck was supposed to be impossible. Money market funds are regulated under the Investment Company Act of 1940 and Rule 2a-7 specifically, which requires them to invest in high-quality, short-term securities and maintain strict maturity limits. The regulatory framework promised that a dollar in a money market fund was as safe as a dollar in the bank, with none of the interest-rate risk of a bond fund.

The Reserve collapse shattered that illusion. Within weeks, institutional investors rushed to redeem shares from other money market funds, causing a systemic run. The Treasury and the Fed intervened with a temporary guarantee program, but the damage was done: savers and companies had learned that money market funds could fail.

Why the Pre-2010 Rules Failed

Before 2010, Rule 2a-7 had looser standards:

• Maturity limits: Individual securities could have maturities up to 397 days (technically less than 13 months)
• Weighted-average maturity (WAM): No cap; some funds ran WAMs of 90–120 days or longer
• Liquidity: No explicit minimum; funds could hold illiquid paper as long as it was “high-quality”
• Diversification: Allowed significant concentration in single issuers or sectors

These gaps mattered. During the 2008 crisis:

• Lehman’s commercial paper (debt maturing in 180+ days) was held by major money market funds
• When Lehman filed, the value of its paper became uncertain overnight; mark-to-market accounting rules forced funds to recognize losses
• Investors panicked and withdrew, forcing funds to liquidate holdings at fire-sale prices

The problem was not just Reserve’s exposure. Many other funds had concentrated bets on financial sector commercial paper, and the contagion threatened the entire system.

The 2010 Rule 2a-7 Overhaul

The SEC issued new amendments to Rule 2a-7 effective May 2010. The changes were structural and binding:

Weighted-Average Maturity Cap (60 Days)

Rule 2a-7 now capped the portfolio’s weighted-average maturity at 60 days. This means that on average, every dollar in the fund must mature in 60 days or less. For a fund holding some 1-day paper and some 180-day paper, the portfolio WAM must still not exceed 60 days.

The 60-day ceiling forces funds to continuously roll over and rebalance holdings. Longer-dated commercial paper became incompatible with money market fund strategies, pushing issuers (corporations, banks) to issue shorter-term paper instead or to access the commercial paper market less frequently.

Individual Security Maturity Limits

• Standard: 397 days (unchanged, but now stricter in practice)
• Floating-rate securities: If floating-rate and tied to Treasury or other stable benchmark, extended to 397 days
• Practical effect: Most funds shortened holdings to 30–90 days to stay within the 60-day WAM

Enhanced Liquidity Standards

The 2010 rule introduced explicit liquidity minimums:

• At least 10% of the portfolio in securities maturing within one day (next-day liquidity)
• At least 20% of the portfolio in securities maturing within one week

These floors ensure funds can meet redemptions without forced asset sales, a major source of the 2008 crisis. If 20% of a $1 billion fund matures each week, the fund can cover most normal redemptions without fire-sales.

Credit Quality Tightening

Rule 2a-7 imposed stricter ratings thresholds:

• Securities must be rated in the highest short-term rating category (e.g., “A-1+” or P-1 by Moody’s)
• No securities rated below the top two categories

This eliminated exposure to speculative-grade paper (like Lehman’s, which fell below top tier after its problems emerged).

The 2014 Amendments: Further Tightening

The 2008 crisis exposed another gap: redemption pressure. During a crisis, even high-quality funds face “runs” as investors flee to safety. The SEC’s 2014 amendments added two tools:

Liquidity Fees

Funds may now impose temporary fees on redemptions if liquidity falls below 10%. If the fund faces heavy redemptions and asset quality deteriorates, the fund can charge up to 2% as a redemption fee, effectively discouraging panicked withdrawals.

Redemption Gates

If liquidity falls below 10%, the fund may suspend redemptions entirely for up to 10 business days, halting outflows and forcing remaining investors to stay put. This prevents cascading panic.

These tools are controversial—they violate the promised “at any price, at any time” liquidity of money market funds—but the SEC argued they are necessary to prevent runs and preserve the system.

Who Was Affected?

Prime money market funds (those investing in corporate and bank commercial paper) bore the brunt of 2010 reforms. They had to shorten maturities, reduce concentration, and accept lower yields. Yields fell further after 2010 reforms were implemented, making money market funds less attractive to institutional investors seeking yield.

Treasury and municipal money market funds were less affected, because government securities are less credit-sensitive and rarely default.

The 2010 reforms also had spillover effects:

• Commercial paper markets shortened overall maturity. Companies now issue more 30-day paper and less 90–180-day paper.
• Corporate financing shifted. Firms unable to place longer-dated commercial paper turned to bank credit lines or term loans, increasing leverage elsewhere.
• Institutional cash management diversified. Treasurers moved away from pure money market funds and into repo, T-bills, and commercial paper ladders they constructed themselves.

The Rule’s Impact on Yields and Demand

Before 2008, a money market fund yielded 3–4% annually during normal times, competitive with a savings account or short-term CD. After the 2010 reforms, yields fell to 0.01–0.10%, well below inflation. This made money market funds unattractive for yield-seeking investors.

The Fed’s near-zero rates (2008–2015 and again 2020–2021) compounded this. Investors abandoned money market funds for higher-yielding alternatives: certificates of deposit, bond funds, or equities. Total assets in money market funds peaked near $2.8 trillion in 2009 and fell to ~$2 trillion by 2015.

From the regulator’s perspective, this was acceptable—safety over yield. From the investor’s perspective, money market funds became a low-return parking lot for emergency funds, not a yield-generating tool.

Ongoing Compliance and Market Structure

Today, money market funds remain major holders of Treasury bills, commercial paper, and repurchase agreements. The Rule 2a-7 framework is embedded in fund prospectuses and daily compliance monitoring. Most funds report their WAM, liquidity percentages, and credit composition quarterly, allowing investors to verify Rule 2a-7 compliance.

The 60-day WAM has reshaped short-term debt markets. Companies issuing commercial paper now issue in 1–90 day buckets to appeal to money market funds. Banks have adapted their funding strategies to issue shorter-term commercial paper or certificates of deposit.

Lessons and Limitations

The 2010 rule addressed structural fragility but left two vulnerabilities:

1. Diversification risk: Rule 2a-7 still permits concentration in single issuers (up to 5% for top-rated names). A major bank failure could still cause losses to money market funds holding its paper, though the 60-day maturity cap limits exposure duration.

2. Redemption gate risk: The 2014 liquidity-fee and gate provisions are circuit-breakers, not preventatives. A fund can still impose gates and fees during a crisis, which may devastate remaining investors who cannot redeem.

The framers of the 2010 rule understood these limits but believed the 60-day WAM and liquidity floors would prevent systemic crises from starting. The rule has held for 14 years without another fund breaking the buck, validating the approach so far.

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