Interest rate "gap" management has become an increasingly important part of bank funds management over the past decade. This management technique matches liabilities to assets of similar maturity lengths and risk classes.

As interest rates have become more volatile and have climbed to historically unprecedented high levels, the degree to which variable-rate assets are different from variable rate liabilities (or, in other words, the amount of variable-rate assets supported by fixed-rate funds) has caused concern. This "gap"-really an imbalance-measures the exposure of bank net interest margin, that is, interest income less interest expense, to unexpected changes in market interest rates.