The interbank lending market is a market in which banks lend funds to one another for a specified term. Most interbank loans are for maturities of one week or less, the majority being overnight. Such loans are made at the interbank rate (also called the overnight rate if the term of the loan is overnight). A sharp decline in transaction volume in this market was a major contributing factor to the collapse of several financial institutions during the financial crisis of 2007–2008.
Banks are required to hold reserves of an adequate amount of liquid assets, such as cash, to manage any potential bank runs by customers. To remain compliant, those banks with less than the required liquidity will borrow money and pay interest in the interbank market, while those with excess liquid assets will lend money and receive interest.
The interbank rate is the rate of interest charged on short-term loans between banks. Banks borrow and lend money in the interbank lending market in order to manage liquidity and satisfy regulations such as reserve requirements. The interest rate charged depends on the availability of money in the market, on prevailing rates and on the specific terms of the contract, such as term length. There is a wide range of published interbank rates, including the federal funds rate (US), the LIBOR (UK) and the Euribor (Eurozone).