Small-cap stock valuations are worrying some investors, including top fund manager Donald Yacktman.

“It’s a hard place to find a lot of bargains right now,” Yacktman told Bloomberg of the current market. “It doesn’t surprise me that this market, particularly small-caps, could be pretty highly valued and way out of whack.”

The Russell 2000 small-cap index has rallied for seven straight quarters, the longest stretch ever, according to Bloomberg, pushing valuations 26% above where they were at the height of the 1990s bull market. Overall the index is up about 250% since the current bull began. The Russell 2000 is trading for 49 times reported earnings, well above its P/E of 39 at the height of the tech bubble , Bloomberg says. The large-cap S&P 500 has a P/E of 17.2, close to its average since 1937, according to data compiled by Bloomberg and Standard & Poor’s.