Only place to go is ... down
The debate over active managements skill vs. luck will always carry on, but credence to the former will often cite a manager's ability to perform well and keep performing well. In its most recent SPIVA Scorecard, S&P Global looked at how well the top-quartile managers from three years earlier have maintained that performance.
Of those managers that were in the top 25% of their respective universes for the 12-months ended Sept. 30, 2017, no more than 13% remained there after three full years of performance. Small and multicap funds were relatively more persistent compared to large and midcaps, with only 8.1% of the total universe's top performers keeping it going two years later.