Daniel, Gilles; Sornette, Didier; Wöhrmann, Peter - 2008
tests of performance suffer from the look-ahead benchmark bias, when they use the assets constituting the benchmarks of …-ahead benchmark bias can exhibit a surprisingly large amplitude for portfolios of common stocks (up to 8% annum for the Samp;P500 … running top 500 US capitalizations to demonstrate that this bias can account for a gross overestimation of performance metrics …