Never mind the FANG block of internet giants. Never mind drugmakers or biotechs. The smart money’s new obsession is the old economy: industrial stocks.

So says RBC Capital Markets after studying quarterly filings of more than 300 hedge funds. By aggregating their holdings in each sector and comparing them to the market over time, strategists led by Lori Calvasina found that machinery and equipment makers have the “most crowding risk.” That’s because fund managers have earmarked more money to the group than their representation in benchmarks with ownership swelling past historic norms.

It’s paying off, at least for now, as industrial shares have led the equity rally this year, jumping almost 18 percent for the best performance among 11 S&P 500 major groups. Part of the gains are likely driven by optimism over U.S.-China trade talks, an issue that has held the likes of Boeing Co. and Caterpillar Inc. hostage with tensions rising over the past year.

But Calvasina urges investors to be alert to the risk of unwinding. That is, too much money is chasing the same stocks and when it pulls out, the decline is that much worse. Just look at what happened last year with the FANG complex of Facebook, Amazon, Netflix and Google’s parent Alphabet. The quartet bore the brunt of selling during the March-April sell-off, and again in the fourth quarter.

“In our experience, crowded names among active managers, including hedge funds, are usually crowded for a reason (good fundamentals),” Calvasina wrote in a note Thursday. “That being said, we still think positioning is a risk factor worth monitoring. When crowded trades unwind, it tends to be painful and difficult for investors to get out in time. 2018 is a case in point.”

The elevated exposure to industrial stocks stands in contrast with a retreat from stocks broadly. As RBC data showed, equity holdings by hedge funds as a percentage of the S&P 500’s market value have fallen to the lowest level since 2012.

This article was provided by Bloomberg News.