$7.96 Trillion Is Parked in Money Market Funds. The Fed's Overnight Repo Buffer Holds $300 Million.

Money market funds are holding $7.96 trillion right now. That's just below the record of nearly $7.98 trillion set a few weeks earlier, and it followed a $72 billion inflow in the week ended October 7 alone. A fed funds rate of 3.75% to 4.00%, a level that didn't exist eighteen months ago, is pulling cash out of checking accounts and into instruments that actually pay for it.

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Most of that money isn't chasing yield for its own sake. Government money funds, the ones holding Treasury bills and repo backed by Treasury collateral, drove most of the latest surge. Corporate treasurers and retail savers alike are parking cash somewhere that pays close to 4% and still lets them pull it out the same day, which beats a bank savings account paying under 1% and beats the hassle of laddering T-bills by hand.

What Changed

The more interesting number isn't the $7.96 trillion. It's the roughly $300 million sitting in the Fed's overnight reverse repo facility, known as ON RRP. That facility peaked above $2.55 trillion on December 30, 2022, back when the Fed's post-pandemic balance sheet had left the financial system swimming in excess cash. Three years of quantitative tightening drained that excess, and ON RRP absorbed almost the entire hit. Balances fell to around $800 billion by the end of 2023, continued sliding through 2024 and 2025, and now sit close enough to zero that the facility barely functions as a buffer anymore.

That drainage is why the Fed stopped shrinking its balance sheet on December 1, 2025, a decision it announced at its late-October meeting that year. Officials described the move as proactive: bank reserves still had room above the level where funding markets would start to strain, but the ON RRP cushion that had absorbed QT's effects for three years was running out. Once that buffer empties, any further balance sheet runoff stops showing up in idle cash and starts showing up directly in bank reserves, the number regulators actually watch for stress. The Fed chose to stop before testing that transition, not after.

Why It Matters

Here's the mechanism worth understanding. When the Fed shrinks its balance sheet, something in the financial system has to shrink with it, either reserves or ON RRP balances. For most of 2023 through 2025, ON RRP did almost all of the shrinking, which let banks keep comfortable reserve levels the whole time. That's no longer available as a shock absorber. Bank reserves, now at $3.03 trillion and sitting inside the Fed's self-described $2.8 trillion to $3.2 trillion "ample" range, are the only cushion left, and nobody at the Fed wants to find out in real time how thin that cushion actually is.

What makes this cycle unusual is that the Fed is doing two seemingly contradictory things simultaneously. It ended balance sheet runoff, a mildly expansionary move for liquidity, within the same year it restarted rate hikes, taking the fed funds target back up to 3.75% to 4.00% after a September increase. Rate policy and balance sheet policy aren't always pointed the same direction, and investors used to a simple "hiking means tightening everywhere" framework are getting a reminder that plumbing and policy rates are separate levers. The 10-year Treasury's own perch near a 24-year high reflects the rate side of that story more than the balance sheet side, but both are happening at once, and both show up in the same bond market.

What to Watch Next

Repo rate stability is the gauge to watch now that ON RRP can no longer mask reserve pressure. SOFR sat at 3.87% on October 8, just under the effective fed funds rate of 3.88%, and the spread between the lowest and highest percentile of trades was still a tight 12 basis points as of early October. That's a market functioning normally. A sudden widening of that spread, or a renewed spike in the MOVE index, which touched its highest level since March 2026 just weeks ago, would be the first sign that reserves are tighter than the headline $3.03 trillion number suggests.

The calendar matters too. NY Fed President John Williams has already signaled he may need to deliver one more hike before year-end, and the next FOMC decision lands October 28. Layer onto that the Treasury General Account, which fell to roughly $880 billion after a fiscal year-end drawdown and will likely get rebuilt through bill issuance in the coming weeks, pulling cash away from the private sector in the process. That rebuild will compete for the same buyer base as everything else the Treasury and corporate borrowers are selling, including the record pace of investment-grade bond issuance tied to AI infrastructure spending that's already competing with the Treasury's own deficit financing needs.

The Pulse24 Take

None of this means a repo crisis is coming. SOFR's trading range is calm, bank reserves are still inside the Fed's comfort zone, and the Fed proved in December 2025 that it would rather act early than wait for stress to show up. But the margin for error has genuinely narrowed. For three years, a trillion-dollar-plus buffer sat between QT and any real liquidity problem. That buffer is effectively gone now, and the people running Fed policy know it, which is the actual reason balance sheet runoff ended months ahead of schedule even as rate hikes resumed.

The lesson for anyone watching markets rather than running them is that "ample reserves" is a range, not a guarantee, and the range just got a lot less forgiving. Keep an eye on SOFR's spread and the MOVE index rather than the headline fed funds rate if you want an early read on funding stress. The rate decisions get the headlines. The plumbing underneath them is where the next surprise is more likely to show up first.