If the average maturity of a bank’s liabilities is less than that of its assets, it is said to be running an unmatched book. The term is commonly used with the Euromarket. Term also refers to the condition when a firm enters into OTC derivatives contracts and chooses to hedge that risk by not making trades in the opposite direction to another financial intermediary. In this case, the firm with an unmatched book hedges its net market risk with futures and options, usually. Related expressions: open book and short book.