With the Dow closing Thursday's trading session 165 points down, the market's bears took their marching orders from a big rally in 10-year Treasury notes, the managing director of San Diego based investment firm HighTower told CNBC.
Treasury yields dropped below 2.50 percent for the first time since last October as prices rose, signaling to traders that the economy wasn't as sound as once believed, said David Molnar, a partner and managing director at HighTower. Molnar told investors to ignore the move under 2.50 percent "at your own peril."
"The bond market is signaling the economy is not as strong as Wall Street and economists were telling us it was going to be, and it's not just weather-related," Molnar said on "Closing Bell."
Robert Pavlik, the chief market strategist for Banyan Partners, told CNBC on Thursday that worries about growth should persist throughout the summer. Some attributed Thursday's selloff to cautious comments from hedge fund titan David Tepper, who told investors Wednesday to not be "too fricking long right now."
"You can point to Europe being a concern," Pavlik said later on "Closing Bell." "You can point to the comments out of [David] Tepper, but I think it's really a concern about growth going forward. Is there going to be enough growth going forward to sustain this market at this level?"
Pavlik said the ongoing rotation out of fast-growing tech and biotech stocks that made for volatile trading sessions in recent months was not a flow into value, dividend stocks. It was a flight to safety, he said, and now that trend has manifested in the bond market with dropping yields.