Art Cashin said the stock market is waiting for earnings season to "really build to a crest" around the middle of the week.
Cashin, UBS' director of floor operations at the NYSE, told CNBC's Mary Thompson around midday, "People are waiting to see how much of this financial engineering is going to continue."
Cashin thinks that so far earnings have been "good" but it's not clear the numbers are evidence of underlying strength.
"I think what they're going to wait and see is the cumulative effect of earnings and that should crest about Wednesday. So, late Wednesday, early Thursday, we'll get a sense, I think, of how the market sees earnings season."
On technicals, Cashin sees some "near-term resistance" for the around 1869 to 1874.
Just after he spoke, the S&P was trading just below the bottom of that range.
—By CNBC's Alex Crippen. Follow him on Twitter @alexcrippen.