The geometric average of the holding period yields to an investment portfolio (Investment Analysis and Portfolio Management, Seventh Edition (2003)). TWRs are commonly used in the investment industry to measure the performance of an entity (e.g. fund, investment, property). The TWR formulas isolate the performance of the entity by removing the timing effect of cash contributions and distributions from the entity's ending fair value. TWRs measure performance over a specific period regardless of the size of the investment or timing of external cash flows.