Investment managers are doubling down on the hottest stocks of 2017 -- and it’s paying off.

Funds tracked by Bank of America Corp. own the highest percentage of technology stocks on record compared to their benchmark. It’s a sector that’s carried U.S. stocks to new highs, leading the S&P 500 Index with a nearly 20 percent gain in 2017. And it’s giving active managers a boost they haven’t seen in more than two years.

Of course, not all technology stocks are created equal. The returns in tech are top-heavy, dominated by Facebook Inc., Amazon.com Inc., Netflix Inc. and Google’s parent Alphabet Inc., also known as the FANG stocks, as well as Apple Inc. Those five companies alone account for more than a quarter of the S&P 500’s advance this year.

Rarely ones to shun the herd, active funds are now 71 percent overweight in the FANG companies after making the biggest move from value to growth since 2008, according to Bank of America.

“The tech stocks obviously continue to be the key group to keep an eye on,” Matt Maley, a strategist at Miller Tabak & Co., wrote in a note to clients Tuesday. “They are over-bought on a near-term and intermediate-term (and even long-term) basis, but that has been true every day for the past few weeks.” 

The move toward growth and momentum stocks further cements active managers’ distrust in the value trade. Value had a record stretch last year that was predicated on economic expansion, the anticipation of pro-growth policies and a predicted pick up in inflation. But as those shares -- and expectations -- stalled, active managers are finding it hard to fight the crowd.

So far, the shift to growth and momentum from value appears to be behind an improving hit rate for active funds. The percent able to beat their benchmark this year stands at its highest since February 2015, Bank of America data show.

The tech-powered rally has catapulted the sector to a price-to-earnings ratio of 24.4, or 41 percent above the 10-year average. But as Google and Amazon stretch to nearly $1,000 a share, not everyone is comfortable with the valuations. Investors pulled more than $716 million from the most popular technology exchange-traded fund last week -- the $17.4 billion Technology Select Sector SPDR Fund, or XLK -- its largest weekly outflow in over a year, data compiled by Bloomberg show.

“Most everybody remembers 2000, so they might be getting a little nervous with this development,” said Maley. “I just wonder how many people have said to themselves, ‘If AMZN gets to $1,000, I’m going to take at least some profits.’”