As passive funds eclipse their active counterparts in assets, active manager performance may be catching up to the indexes, according to Morningstar.

In August, assets in U.S. index-based equity mutual funds and ETFs for the first time exceeded the assets in actively managed funds, according to Morningstar.

U.S. equity index funds now account for $4.271 trillion in assets, while there are $4.246 trillion in active funds. August fund flows were the straw that broke the actively managed camel’s back: Nearly $89 billion flowed into passive funds while $124 billion exited active strategies.

Morningstar also published its semiannual Active/Passive barometer examining the success rate of actively managed mutual funds, and the overall picture was bleak for managers: Just 23% of them beat their passive benchmarks over the 10-year period ended in June.

Yet active U.S. stock funds have fared significantly better recently, with 48% of managers beating an average passive peer in the 12 months ended June 2019. That’s up from 37% in the year that ended in June 2018.

When Morningstar took a more granular view of active funds and focused on U.S. equity growth, it found that 66% of active managers were beating their respective indexes.

All told, active managers were able to increase their one-year success rates, the proportion of funds outperforming their benchmark index, in 11 out of the 20 categories Morningstar examined.

Morningstar once again found a strong correlation between a fund’s fees or expenses and its success rate—the cheapest quintile of funds enjoyed a 10-year success rate of 33%, while the most expensive quintile of funds posted a 14% 10-year success rate.

Across all 20 Morningstar categories, the 10-year success rate varies widely, from a peak of 82.4% of active foreign small-cap/mid-cap blended funds beating a representative passive composite in the decade ending in June, to just 7% of U.S. large-cap value funds overcoming their benchmark in the same period.

Morningstar’s Active/Passive Barometer measures the performance of more than 4,000 U.S. active mutual funds against their passive peers, encompassing nearly $12.5 trillion in assets, or 64% of the U.S. fund market.