Longtime trader Art Cashin believes Wednesday's across-the-board rally could be the one to end a selloff in momentum stocks.
Cashin, UBS' director of floor operations at the NYSE, said traders watched several big vital signs from Tuesday's volatile trading session carry over into Wednesday' triple-digit gains on major stock market averages.
"I know that sounds like inside baseball mumbo jumbo to some of the people out there, but those are the kinds of vital sign checks that we on the floor give," Cashin said on "Squawk on the Street." "I wrote this morning that chances are the momentum selloff was over and we'll move on to to other things".
Wall Street has a shortened trading week with Good Friday closing markets. Cashin said if tensions between Ukraine and Russia boil over into a military action, market volatility could come roaring back.
—By CNBC's Jeff Morganteen.