DMPFED.ORG — Paid Tier Preview
Diagram 1 of 5 · Paid Tier · From "Why Does the Government Borrow Money It Has the Power to Create?"

The Interest Rate Corridor

Four rates, one job: keep the actual market rate trading inside a range the Fed sets on purpose. Here's what each one does today, and where they've all been for the last two years.

■ Documented
Acronym key
FOMC
Federal Open Market Committee — the Fed's rate-setting body. Meets 8 times a year to decide the target range.
IORB
Interest on Reserve Balances — the rate the Fed pays banks to hold reserves. The main steering lever.
ON RRP
Overnight Reverse Repo (facility) — where money-market funds can always park cash overnight. The floor.
EFFR
Effective Federal Funds Rate — the actual rate banks trade at overnight. The number reported as "the Fed rate."

Where each rate sits

FOMC TARGET RANGE 3.50–3.75% 3.75% CEILING Discount rate 3.65% IORB Fed pays banks this 3.63% EFFR The reported "Fed rate" 3.50% FLOOR ON RRP facility
Discount rate — the ceiling

What a bank pays to borrow directly from the Fed as a last resort. Nobody wants to be here — using it signals the bank couldn't find funds anywhere cheaper.

IORB (Interest on Reserve Balances) — the main lever

What the Fed pays banks just to hold reserves and do nothing. No bank lends cheaper than this risk-free rate, so raising or lowering it pulls everything else with it.

EFFR (Effective Fed Funds Rate) — the actual rate

What banks actually trade at overnight. This is the number in the headlines. It isn't set directly — it's the market settling just under IORB.

ON RRP (Overnight Reverse Repo) — the floor

Money-market funds and other non-banks can always park cash here overnight, so almost nothing trades below it.

Nobody "sets" the fed funds rate directly. The Fed sets the ceiling, the floor, and the main lever in between — and lets the actual rate find its own level inside that corridor.

How the corridor has moved

Same four rates, over the last two years. The whole corridor has walked down 175 basis points since September 2024 — in two clusters of three cuts each, with long stretches of nothing in between.

5.50% 5.00% 4.50% 4.00% 3.50% −100bp Sep–Dec '24 −75bp Sep–Dec '25 Aug '24 2025 · steady Jul '26
Discount rate
IORB
EFFR (dashed)
ON RRP

Since September 2024: six cuts, 175 basis points total, delivered in two back-to-back clusters of three — one closing out 2024, one closing out 2025 — with about nine quiet months between them and, so far, seven more in 2026.

How this is drawn: the target-range dates and values (5.50–5.25% down to 3.75–3.50%) are the FOMC's own documented decisions. IORB and ON RRP are shown at the Fed's standard operating spread for the current ample-reserves regime — IORB roughly 10bp below the top of the range, ON RRP at the bottom, discount rate at the top — applied consistently across the window; the exact spread has shifted by up to 5bp at individual meetings. EFFR is shown tracking just under IORB, as it has throughout this period.

Two separate flows people conflate

This is the part the multiplier story gets wrong: it treats these as one mechanism. They're two, at two different levels of the system, and neither waits for the other.

Flow 1 — the Fed and a bank
FED
buys a Treasury security
→ credits →
BANK'S RESERVE ACCOUNT
at the Fed (+reserves)

A wholesale-level accounting entry. No cash you or I would ever touch changes hands — it's a credit between the Fed and a bank's account.

Flow 2 — a bank and a borrower
BANK
issues a loan
→ creates →
BORROWER'S DEPOSIT
same instant (+deposit)

This is where the money you actually spend comes from. It happens the moment the loan is approved, not because the bank went looking for spare reserves to lend out.

Put together

The corridor at the top of this page only governs Flow 1 — the wholesale price banks charge each other for reserves. It has no direct grip on Flow 2 — how much banks lend into the real economy — because that decision is limited by bank capital and loan demand, not by how many reserves a bank happens to be sitting on. The Fed can move the price of reserves. It cannot ration the quantity of loans. That's the entire gap between the corridor picture on this page and the old multiplier picture in the textbook, in one sentence.

Rates as of July 1, 2026: EFFR 3.63%, target range 3.50–3.75%, IORB 3.65% (FRED / Federal Reserve Board H.4.1; SOFRRate.com policy-rate tracker). Corridor mechanics: Federal Reserve Board, "Interest on Reserve Balances FAQ"; FRED Blog, "Rates related to monetary policy" (Ihrig & Wolla). Rate-cut history: Federal Reserve FOMC meeting calendars and statements (Sep 18 & Nov 7 & Dec 18, 2024; Sep 17 & Oct 29 & Dec 10, 2025); Bankrate and Forbes Advisor federal funds rate histories; Advisor Perspectives, "Fed's Interest Rate Decision: June 17, 2026." Discount-rate-to-range-top convention: Federal Reserve Board press release, March 15, 2020. Tiered Documented — all rates and dates are drawn from Federal Reserve, FRED, or CRS primary data; the IORB/ON RRP spread applied to historical dates is a documented standard convention, noted above.
← Back to the full explainer