The European Central Bank's unprecedented measures to combat disinflation may have helped boost U.S. stocks to record levels Thursday, but Wall Street still remains full of skeptics, veteran trader Art Cashin told CNBC.
"There's still some doubts about the efficacy of it," said Cashin, UBS' director of floor operations at the NYSE. "[ECB President Mario Draghi] did many of things people expected him to do. And we saw the currency markets whip around, even the bond market whip around a little bit. I think there is still some doubt out there."
Speaking to CNBC at midday, Cashin said he had expected the S&P 500 to see a big pop after breaking through a resistance band of 1,931 points. That didn't happen, and it's evidence that traders are keeping one eye on Friday's U.S. payroll numbers and another on the rise in the euro after Draghi's announcement, he added.