2019 Repo Spike: When Overnight Cash Ran Dry

Key Takeaways

• Overnight repo rates spiked from about 2 percent to roughly 10 percent on September 17, 2019.
• A tax-day cash drain met record-low bank reserves, so demand for funding outran supply.
• The Fed restarted repo operations, its first such intervention since the 2008 crisis.
• Plentiful-looking reserves can turn scarce fast when they are unevenly distributed.

Background

The repo market is where banks, dealers, money funds, and other large players borrow and lend cash overnight against safe collateral, almost always US Treasuries. A firm sells a Treasury security today and agrees to buy it back tomorrow at a slightly higher price. The price gap is the interest, and the deal is a repurchase agreement, or repo. Trillions of dollars change hands this way every day, and it is how the financial system funds its inventory of bonds.

Repo rates normally track the Federal Reserve's policy rate closely. In September 2019 the Federal Open Market Committee was targeting a federal funds range of 2.00 to 2.25 percent, so overnight repo usually traded near that level. The Secured Overnight Financing Rate (SOFR), the published benchmark built from repo trades, sat around 2 percent in the days before the spike.

The setup that mattered was the supply of bank reserves. Reserves are the cash banks hold at the Fed, and they are the raw material of overnight lending. After years of post-crisis balance-sheet expansion, the Fed had spent 2018 and 2019 shrinking its holdings, which pulled reserves out of the system. By mid-September 2019 aggregate reserves had fallen to a multi-year low of less than $1.4 trillion, with the Fed's own figures showing a drop to about $1.34 trillion on September 16, the lowest since 2012.

At the same time, the supply of Treasury collateral that dealers had to finance was unusually large. The OFR later noted that net Treasury positions held by primary dealers had reached an all-time high. So the system entered mid-September with more bonds to fund and less cash to fund them, a brittle combination that needed only a trigger.

What Happened

The trigger arrived on September 16, 2019, when two large cash drains landed on the same day. Companies paid quarterly corporate taxes, and about $54 billion of long-term Treasury debt settled, meaning buyers had to hand cash to the Treasury. Both flows moved money out of bank reserves and into the government's account. The Fed estimated that reserves in the banking system fell by about $120 billion over two business days.

The acute phase unfolded fast:

• September 16, 2019: SOFR printed at 2.43 percent, 13 basis points higher than the prior business day, while the effective federal funds rate sat at 2.25 percent, the top of the FOMC's target range.
• September 17, 2019: Overnight repo rates surged. SOFR rose above 5 percent (about 5.25 percent on common measures), and intraday repo trades reached as high as roughly 10 percent. The effective federal funds rate moved to 2.30 percent, above the top of the FOMC's range.
• September 17, 2019 (morning): The Federal Reserve Bank of New York announced an overnight repo operation offering up to $75 billion and added about $53 billion of reserves, the Fed's first repo intervention since the 2008 financial crisis.
• September 18 to 20, 2019: The New York Fed kept injecting cash daily and added term repos, lending for as long as 14 days, to spread relief across the quarter-end.
• By late September 2019: Rates settled back near the target range as the daily operations took hold.

The strange feature of the spike was how few trades happened at the extreme rates. The OFR found that 70 to 80 percent of the day's repo trades had already been negotiated before the spikes erupted, which means only a limited set of firms paid the eye-watering levels. The headline 10 percent was real but thin, a sign of a market that briefly could not clear rather than one in broad panic.

Why It Happened

The spike was not caused by credit fear or a failing institution. It was a plumbing problem: the demand for overnight cash exceeded the supply at the going rate, and the price had to jump to clear the gap. Three forces combined.

First, reserves had grown scarce. Surveys had suggested reserves would not bite until they fell under about $1.2 trillion, so the Fed believed it had room. The September stress showed the true scarcity point was higher, because reserves are not spread evenly. A handful of large banks held much of the cash and, for their own liquidity and regulatory reasons, were reluctant to lend it into repo even at attractive rates. Plentiful reserves on aggregate can still be scarce where and when they are needed.

Second, the tax-and-settlement drain hit at the worst moment. Corporate tax payments and the $54 billion Treasury settlement on September 16 pulled roughly $120 billion of cash out of the banking system over two days and parked it at the Treasury. That mechanical transfer left less cash chasing the same large pile of Treasury collateral, and the imbalance pushed rates up.

Third, market frictions amplified the move. The OFR pointed to limited transparency and market segmentation, where some participants did not see how tight cash had become, or could not move money quickly to where it was scarce. Dealers also face balance-sheet limits, so they could not freely expand their lending to soak up the demand. The result was a localized cash shortage that spilled into a benchmark spike before the Fed stepped in.

The deeper lesson is that the Fed had drained reserves to a level it could not safely judge in advance. The system had been running closer to the edge of scarcity than anyone realized, and a routine calendar event was enough to tip it over.

By the Numbers

• Overnight repo rate, peak: as high as roughly 10 percent intraday on September 17, 2019, up from around 2 percent. (Federal Reserve FEDS Notes; OFR; Brookings)
• SOFR, Sept 16 to 17: 2.43 percent on September 16, then above 5 percent on September 17 (about 5.25 percent on common measures). (Federal Reserve FEDS Notes)
• Effective federal funds rate: rose to 2.30 percent on September 17, above the FOMC's 2.00 to 2.25 percent target range. (Federal Reserve FEDS Notes)
• Bank reserves: a multi-year low of less than $1.4 trillion in mid-September, about $1.34 trillion on September 16, the lowest since 2012. (Federal Reserve FEDS Notes; OFR)
• Cash drain: about $120 billion of reserves left the banking system over two business days, including about $54 billion of Treasury debt settling on September 16. (Federal Reserve FEDS Notes)
• First Fed repo operation: September 17, 2019, offering up to $75 billion and adding about $53 billion of reserves, the first such intervention since the 2008 crisis. (Federal Reserve FEDS Notes; contemporaneous reporting)
• Trades pre-negotiated: 70 to 80 percent of the day's repo trades were already done before the spikes hit. (OFR)
• Reserve-management purchases: about $60 billion per month of Treasury bills, announced October 11, 2019, starting October 15. (Federal Reserve FEDS Notes; Chicago Fed Letter)

Aftermath

The immediate damage was contained. No bank failed, no fund broke, and rates returned toward the target within days once the New York Fed began its operations. The lasting effect was a change in how the Fed runs its balance sheet and its plumbing.

The repo operations did not stop after the spike. The New York Fed kept conducting daily overnight repos, offering at least $75 billion each, through October 10, 2019, and added term repos lending for up to 14 days. The term auctions grew over the autumn as quarter-end and year-end pressures loomed, with term repo capacity scaled up into December 2019. The Fed treated overnight funding as something it now had to backstop continuously, not occasionally.

On October 11, 2019, the Fed announced a larger fix. Starting October 15, it would buy Treasury bills at a pace of about $60 billion per month, at least into the second quarter of 2020, to rebuild reserves to a comfortable level. The Fed labeled this "reserve management purchases" and stressed it was not a change in monetary policy stance, not quantitative easing. Critics noted the balance sheet was expanding either way. The distinction was real in intent, since the goal was funding stability rather than easing financial conditions, but the line was fine enough that markets debated it for months.

The episode also reshaped policy thinking. The Fed concluded it had let reserves fall too far and committed to running an "ample reserves" regime with a larger cushion. In July 2021 it introduced the Standing Repo Facility, a permanent backstop that lets eligible firms borrow cash against Treasuries at a set rate, so a 2019-style scramble can be capped without an emergency announcement. No one was charged or sanctioned, because nothing illegal happened. The September 2019 spike was a design flaw in the system's calibration, and the response was structural rather than punitive.

Lessons for Investors

1. Liquidity is a system property, not just a number. Aggregate reserves of nearly $1.4 trillion looked plenty, yet cash still ran short because it was unevenly held and slow to move. When you assess how safe a market is, ask not only how much liquidity exists but where it sits and how fast it can travel to where it is needed.

2. Calendar events cluster risk. The spike landed on a tax-payment day that coincided with a large Treasury settlement. Known, scheduled cash drains can stack up and overwhelm a system already running tight. Quarter-ends, tax days, and big settlement dates are predictable pressure points worth watching.

3. The plumbing matters even when nothing is failing. No institution was insolvent in September 2019, yet a core funding market briefly seized. Problems in short-term funding can move prices and force central-bank action without any underlying credit loss, so funding stress is its own risk category.

4. Policy guidance can be wrong about its own limits. Surveys put the reserve scarcity point below $1.2 trillion, and the real threshold proved higher. Even careful official estimates of where a system breaks are guesses until tested. Treat thresholds as approximate, and leave room for the line to be in the wrong place.

5. Labels do not change cash flows. The Fed called its T-bill buying "reserve management," not QE, and the intent differed, but its balance sheet grew regardless. When you analyze a policy move, follow the actual flows of money and collateral rather than the name attached to them.

Frequently Asked Questions

What was the 2019 repo spike in simple terms? The 2019 repo spike was a sudden jump in the cost of borrowing cash overnight against US Treasuries, which rose from about 2 percent to roughly 10 percent on September 17, 2019. It was a short-term funding shortage, not a credit crisis, and the Federal Reserve stepped in with cash to calm it.

Why did the 2019 repo spike happen? Bank reserves had fallen to a multi-year low while the pile of Treasury collateral needing funding was near a record, so the system was already tight. On September 16 a corporate tax deadline and a large Treasury settlement drained about $120 billion of cash over two days, and demand for overnight funding outran supply.

How high did rates go in the 2019 repo spike? Overnight repo rates reached as high as roughly 10 percent intraday on September 17, 2019, up from around 2 percent. SOFR rose above 5 percent that day, and the effective federal funds rate slipped above the FOMC's 2.00 to 2.25 percent target range.

Could a repo spike happen again today? The mechanics still exist, since reserves can still grow scarce and calendar drains still hit. The Fed has added safeguards, including an "ample reserves" stance and the Standing Repo Facility launched in 2021, which provides a permanent cash backstop against Treasuries to cap a similar scramble.

What is the main lesson from the 2019 repo spike? Liquidity can look abundant in total yet be scarce where it is needed, so a routine cash drain can break a core funding market without any institution failing. Watch how reserves are distributed and how easily cash can move, not just the headline amount.

Sources

1. Federal Reserve Board (FEDS Notes). What Happened in Money Markets in September 2019? February 27, 2020. https://www.federalreserve.gov/econres/notes/feds-notes/what-Happened-in-Money-Markets-in-September-2019-20200227.htm
2. Office of Financial Research, U.S. Department of the Treasury. OFR Identifies Factors That May Have Contributed to the 2019 Spike in Repo Rates. April 25, 2023. https://www.financialresearch.gov/the-ofr-blog/2023/04/25/ofr-identifies-factors-that-may-have-contributed-to-the-2019-spike-in-repo-rates/
3. Office of Financial Research, U.S. Department of the Treasury. Anatomy of the Repo Rate Spikes in September 2019 (Working Paper 23-04). 2023. https://www.financialresearch.gov/working-papers/2023/04/25/anatomy-of-the-repo-rate-spikes-in-september-2019/
4. Brookings Institution. What is the repo market, and why does it matter? https://www.brookings.edu/articles/what-is-the-repo-market-and-why-does-it-matter/
5. Federal Reserve Bank of Chicago. Understanding Recent Fluctuations in Short-Term Interest Rates (Chicago Fed Letter No. 423). 2019. https://www.chicagofed.org/publications/chicago-fed-letter/2019/423
6. Federal Reserve Bank of New York. The Market Events of Mid-September 2019 (Economic Policy Review). 2021. https://www.newyorkfed.org/research/epr/2021/epr_2021_market-events_afonso.html

Disclaimer

This article is educational content only and is not financial advice. Nothing here is a recommendation to buy, sell, or hold any security. Consult a licensed advisor before making investment decisions.