Bill Miller’s record-breaking streak of beating the market is finally over. It is the end of a fascinating story

Since 1991, Legg Mason Value Trust of the mutual fund company called Legg Mason has risen at an average annual rate of 15.8%, compared to the 11.9% for the S&P 500. Bill Miller, the fund manager, beat the Standard & Poor’s index of 500 stocks year after year for the past 15...