"Valuations seem to be getting a little toppy here," said Weiss, senior portfolio manager with American Century Investments. "We've ridden this bull market for the last several years and continue to be positioned fairly bullish—overweighting equities and other risk assets."
However, he called the valuation metrics "not anywhere near as compelling" as they were over the past few years.
"The tenor of the bull is changing. And so we are seeing a rotation, and we are indeed rotating our positions from what's essentially a tug of war between mid-cycle stocks and some of the later defensive-oriented issues," Weiss told CNBC's "Power Lunch."