. They found, as the SPIVA studies I’ve cited many times have regularly found, that the longer the investment period, the lower the percentage of managed funds that beat a broad stock index fund like an S&P 500 fund or a total stock market fund.
They also found that as money managers focused their decisions on a small number of stocks, betting more on the quality of their decisions, the greater the odds their performance would trail a broad index fund. So much for brave bets and big commitments.testing the limits of inaction.
In the ten-year period ending March 31, 2023, he found that the do-nothing portfolio was about equal to the S&P 500 index portfolio but less risky due to the accumulated cash holdings. He found similar results for 10-year portfolios ending March 31, 2013, and March 31, 2003.