The funds held by a bank beyond what is required by regulators are termed surplus reserves. These balances represent cash available for lending or investment purposes that exceed the mandatory reserve requirement set by the central bank. As an illustration, if a banking institution is obligated to maintain 10% of its deposits in reserve and it holds 12%, the additional 2% constitutes this type of reserve.
Holding these additional funds can provide institutions with a buffer against unexpected deposit withdrawals or increased loan demand. During periods of economic uncertainty, banking organizations may choose to increase their holdings of these reserves as a precautionary measure. Historically, shifts in these reserve levels have served as indicators of banking system liquidity and risk appetite. Furthermore, central banks sometimes manipulate reserve requirements to influence the overall money supply and credit conditions within an economy.