Investors and advisors using the past performance of actively managed mutual funds and ETFs as a guide for choosing among funds should do so with caution.

According to the latest S&P Dow Jones Indices Persistence Scorecard, very few U.S. funds that placed in the top quartile for performance among their category peers remained in the top quartile over three and five consecutive 12-month periods and over two non-overlapping three-and five-year periods — all ending on March 31, 2018.

(Related: Don’t Expect Active Funds to Outperform in a Bear Market)

Moreover, there was a stronger likelihood that top-performing funds would become worst-performing funds rather than vice versa. Of 364 funds in the bottom quartile, 17% moved to the top quartile over the five-year horizon while close to 26% of top performers fell to the bottom quartile over the same period, according to the scorecard.

Bottom performers, however, had a much higher rate of disappearing either through mergers or liquidations. Slightly more than one-third of large-cap and mid-cap funds in the bottom quartile as well as 29% of the lowest-performing small-cap funds disappeared over the five-year transition matrix.

As in previous Persistence Scorecards, top-performing actively managed equity funds lost their stellar status more frequently than their fixed income counterparts and the top equity performers lost staying power over time.

Only 2.33% of actively managed domestic equity funds that placed in the top quartile as of March 2016, based on three consecutive 12-month periods, remained there by the end of 2018. Small-cap active funds did best — almost 4% of top performers placed in the top quartile two years later, while mid-cap funds performed worse — not one fund in the top quartile as of March 2016 remained there two years later. And only 1% of top-performing large-cap funds in 2016 held that distinction in 2018.

Top-performing actively managed fixed income funds fared better, led by investment-grade short-term bonds funds followed by government short-term funds. Nineteen percent of top-performing investment-grade short funds in the top quartile held that distinction two years later while almost 17% of top quartile government short bond funds did. The number of funds, however, was much smaller than the number of stock funds — just 21 investment grade short funds and six government short funds.

— Check out Why Low-Cost Index Investing Is Not Necessarily Low Risk on ThinkAdvisor.