Repo Rate Spike Event

What Is a Repo Rate Spike?

A repo rate spike is a sudden and dramatic rise in overnight repo rates above the Federal Reserve's target range. The most famous example is the September 17, 2019 episode, when the overnight repo rate (the precursor to SOFR) intraday-spiked to 10% with the Fed funds target at 2.00-2.25%. Repo rate spikes signal acute liquidity stress in money markets and historically have forced emergency Fed intervention.

The post-2019 framework includes the Standing Repo Facility (SRF), an on-demand Fed lending operation that caps how high overnight repo rates can go. The SRF has largely eliminated the risk of severe repo spikes under normal conditions.

Why It Matters for Markets

Repo spikes are a clear signal of reserve scarcity and money market fragility. The September 2019 episode forced the Fed to immediately pivot from QT to balance-sheet expansion ("not QE, but it had the same effect"). Subsequent QT cycles (including the 2022-2024 cycle) have been calibrated to avoid approaching the conditions that produced the 2019 spike.

For traders, repo spikes can disrupt derivatives pricing, cause forced unwinds of leveraged positions, and produce broader cross-asset stress. The 2019 spike contributed to a 1.5% S&P 500 sell-off on the day and triggered weeks of cross-asset volatility.

How to Read the Conditions

Reserve balance level. The September 2019 spike occurred when reserves had fallen to approximately $1.4 trillion. The Fed considers the current "ample reserves" floor to be around $3.0-3.5 trillion. Reserve balances approaching $3.0 trillion would signal scarcity risk.

SOFR-IORB spread. Persistent SOFR readings at or above IORB signal scarcity dynamics. The 2019 spike was preceded by weeks of SOFR running at the top of the target range.

SRF usage. The Standing Repo Facility's daily usage is published on the Fed's H.4.1 release. SRF usage above zero signals stress in the repo market; sustained usage would signal that reserve scarcity is real.

Quarter-end vs persistent moves. Modest SOFR spikes at quarter-ends (March, June, September, December) are normal and expected as bank balance sheets contract. Persistent spikes between quarter-ends signal deeper stress.

Historical Context

The September 17, 2019 repo crisis remains the canonical modern repo spike. Overnight rates spiked to 10% intraday; SOFR closed at 5.25% with Fed funds at 2.25%. The Fed responded with $53 billion of overnight repo operations the same day and continued operations for weeks. By mid-October the Fed had launched a $60 billion/month T-bill buying program to rebuild reserves, completing the pivot from QT to balance-sheet expansion.

Through 2024-2025, the SRF has prevented any repo spike of comparable magnitude. Modest quarter-end pressures (10-30 bp SOFR moves above the target midpoint) have been the worst case observed. The Fed slowed QT in June 2024 to $25B/month in Treasuries (from $60B) explicitly to avoid approaching the conditions that produced 2019.