Effective Federal Funds Rate (EFFR)

What Is the Effective Federal Funds Rate?

The Effective Federal Funds Rate (EFFR) is the volume-weighted median rate at which depository institutions trade unsecured overnight reserves with each other. It is calculated daily by the Federal Reserve Bank of New York from actual transaction data and represents the market-clearing rate within the Fed funds target range. The FRED ticker is EFFR.

The fed funds market, once the dominant overnight money market, has shrunk dramatically since 2008. Today most fed funds volume comes from Government-Sponsored Enterprises (Federal Home Loan Banks, Fannie Mae, Freddie Mac) lending reserves to banks, rather than bank-to-bank lending.

Why It Matters for Markets

EFFR is the FOMC's primary policy instrument. The Fed sets a target range (e.g., 3.50-3.75%) and uses administered rates (Interest on Reserve Balances, ON RRP rate) to keep EFFR within the range. Deviations of EFFR from the target midpoint signal that administered rates may need adjustment.

For trading purposes, fed funds futures are priced on EFFR. The CME's fed funds futures contracts settle on the monthly average EFFR, making them the primary instrument for pricing near-term FOMC decisions. Implied probabilities from fed funds futures are the canonical signal for "what the market expects from the Fed".

How to Read the Print

EFFR vs target midpoint. The EFFR should trade close to the target range midpoint. Persistent deviations (>10 bp) signal that administered rates need adjustment.

EFFR vs SOFR. EFFR and SOFR typically trade within 5-10 bp of each other, with SOFR usually slightly lower because it's secured by Treasury collateral. Large gaps signal stress in either market.

Daily EFFR vs IORB. Interest on Reserve Balances (IORB) is the rate the Fed pays banks on their reserves. EFFR should trade below IORB (banks would rather earn IORB risk-free than lend at lower rates). Persistent EFFR above IORB signals scarcity dynamics.

Historical Context

EFFR data goes back to 1954. The 2010-2015 ZIRP era kept EFFR pinned near 0.10% (the IORB rate at the time). The 2022-2024 hiking cycle drove EFFR from 0.08% in March 2022 to a peak of 5.33% in mid-2023. Post-September-2024 cuts brought EFFR down to the 3.50-3.75% range.

Through 2024-2025, EFFR has traded close to the target midpoint with modest quarter-end deviations. The Fed has been successful at maintaining EFFR within the target range, supported by the abundant-reserves regime and active use of administered rates. A sustained EFFR drift outside the range would signal that QT has gone too far and reserve scarcity is emerging.