DEFINITION of 'Unmatched Book'
An imbalance that occurs when the maturity of a bank's assets, such as loans, does not match the maturity of its liabilities, such as investments and interest-paying accounts, on the balance sheet. The imbalance can be either positive or negative.
Also known as "mismatched maturities."
BREAKING DOWN 'Unmatched Book'
"Mismatched maturities" can also refer to unexecuted forward or spot-market purchases on a foreign-exchange transaction. Still another example is a currency mismatch, where the assets outweigh the liabilities (or vice versa) in a given currency.