The interbank rate refers to the interest rate at which banks lend to and borrow from one another on a short-term basis. In the U.S. context this most commonly means overnight lending in the federal funds market; internationally it may also mean the wholesale exchange rate banks use when transacting foreign currency with each other. These rates underpin most other interest rates and foreign‑exchange prices, but are generally only available to highly creditworthy financial institutions.
Key takeaways
– The interbank interest rate (in the U.S.) usually means the federal funds, the overnight rate banks charge each other to meet reserve and liquidity needs. (Investopedia; FRB)
– The Federal Reserve influences—but does not literally “set”—the interbank/federal funds rate by announcing a target range and using open‑market operations; individual banks negotiate the actual transaction rate. (Board of Governors of the Federal Reserve System)
– Interbank foreign‑exchange rates are wholesale FX quotes used by banks; retail customers pay the interbank rate plus a spread or commission. (Investopedia; OFX)
– Changes in the interbank/federal funds rate ripple through loan, mortgage and deposit rates, and affect borrowing costs and asset prices economy‑wide. (Investopedia; Federal Reserve Bank of St. Louis)
How the interbank interest rate works
– Purpose: Banks must maintain reserves to meet withdrawals and regulatory requirements. When a bank has a shortfall it borrows; when it has excess it lends. These short‑term loans—typically overnight and rarely longer than a week—are priced at the interbank (federal funds) rate. (Investopedia)
– Mechanics: The Federal Open Market Committee (FOMC) sets a target range for the federal funds rate. The Fed implements policy through open‑market operations and other tools (e.g., repos, reverse repos, paying interest on reserves) to steer the market rate toward that target, but the actual transaction rate results from bilateral trades among banks. (Board of Governors; FRB New York)
– Relationship to other Fed rates: The discount rate is the rate the Fed charges banks that borrow directly from the discount window. It is a separate tool and typically sits above the federal funds target to encourage banks to borrow in the market first. (Board of Governors)
– Policy transmission: A lower interbank rate reduces banks’ funding costs and typically lowers interest rates across the economy (mortgages, business loans), while a higher rate increases borrowing costs and can slow activity. Historical examples include near‑zero rates after 2008 and in 2020, and subsequent rate increases in later years. (Investopedia; FRED)
Interbank rate in foreign exchange (FX)
– Definition: The interbank FX rate is the wholesale exchange rate banks quote to each other for large currency transactions. These rates are very close to the theoretical market price and update continuously during market hours. (Investopedia; OFX)
– Who uses it: Banks trade at interbank FX rates primarily to manage their own currency risk and to serve large institutional clients. Retail customers and smaller businesses usually receive a rate that equals the interbank rate plus a markup (spread). (Investopedia)
– Practical implication: When you check an online currency converter you typically see interbank (spot) rates. If you exchange money at a bank or currency provider, expect to pay a spread on top of that rate. (OFX)
Why ordinary consumers don’t get the interbank rate
– The interbank interest rate is reserved for the most creditworthy financial institutions dealing in large, short‑term transactions. Retail lenders and depositors face rates that are the interbank rate plus credit, liquidity and operational premia. Similarly, retail FX customers pay the interbank FX rate plus a dealer spread. (Investopedia)
Practical steps — for different audiences
1) For bank treasury or liquidity managers
• Monitor reserve positions daily: forecast cash flows and intraday balances to reduce costly emergency borrowing.
• Use the Fed’s facilities appropriately: consider overnight repos, the discount window (as a backstop), and intraday overdraft arrangements as part of contingency planning. (Board of Governors; FRB New York)
• Shop short‑term markets: use federal funds, repos, and interbank deposits/term funding to diversify funding sources and reduce concentration risk.
• Hedge interest‑rate mismatches: use short‑term interest rate swaps or futures to stabilize net interest margin when appropriate.
2) For corporate finance / treasurers managing FX and interest risk
• For FX: obtain multiple bank quotes for large conversions; use forwards or options to lock in rates if you have known future needs.
• Netting and concentration: centralize FX flows to reduce the number of conversions and to obtain better pricing from banks.
• Hedging: develop a documented hedging policy (e.g., hedge ratios, permissible instruments) and execute with counterparties you’ve vetted for credit and execution quality.
3) For retail borrowers / savers
• Track Fed communications and key indicators: changes in the federal funds target affect mortgage, auto loan and credit card pricing with a lag. (FRED; Board of Governors)
• Shop and compare effective APRs: lenders add a premium to the benchmark rate—comparison shopping can lower your cost.
• Consider timing and product features: fixed‑rate loans lock in borrowing costs if rates are rising; adjustable‑rate products may start lower but can rise with the market.
• For FX needs (travel or remittance): use dedicated currency providers or banks that publish their exchange rate spreads; for large transfers, request interbank‑level quotes or use an FX specialist. (OFX)
4) For investors and analysts
• Watch the effective federal funds rate and Fed announcements: the Board’s statements and FOMC minutes hint at policy direction and will influence asset prices. (Federal Reserve Board; FRED)
• Monitor money‑market indicators: T‑bill yields, LIBOR/SOFR term rates, and repo rates provide additional short‑term funding cost information.
• Stress‑test portfolios: rising interbank rates may compress credit spreads and increase borrowing costs for leveraged entities; model scenarios for rate shocks.
Important considerations and limitations
– The Fed influences but does not directly fix the federal funds market rate—banks ultimately transact and determine the actual market price within the Fed’s target range. (Board of Governors)
– Interbank markets can tighten in stress periods; central banks may provide liquidity backstops to prevent freeze‑ups (e.g., 2008 crisis and 2020 pandemic responses). (Investopedia; Board of Governors)
– Interbank FX rates are not retail rates: expect spreads, commissions and fees when you exchange currency or send money abroad. (OFX)
Further reading and sources
– Investopedia. “Interbank Rate.”
– Board of Governors of the Federal Reserve System. “Policy Tools: Open Market Operations.”
– Board of Governors of the Federal Reserve System. “Regulatory Reform: Discount Window Lending.” (reservations on discount window use and purpose)
– Federal Reserve Bank of New York. “Effective Federal Funds Rate.”
– Federal Reserve Bank of St. Louis (FRED). “Federal Funds Effective Rate.”
– OFX. “What Is the Market Rate?” /
– Create a brief checklist you can use when comparing loan offers or FX providers.
– Produce an example cash‑flow forecast showing how a treasury team might avoid overnight borrowing.