Is Rolling Exponentially Weighted Estimation Better Than Full Sample: A Backtest Examination of Portfolio Optimization Parameters

The authors use random subsample backtests to examine the effectiveness of exponentially weighted window estimates of the Sharpe ratio for portfolio optimization. They compare the out-of-sample Sharpe ratios of EWM spans of 5, 10, 20, and 30 years against full-sample estimates across various in-sample and out-of-sample periods.