Market highs could have been helped by Europe post Trump speech, Art Cashin says

European investors may have been reassured enough by President Donald Trump's speech to Congress to reinvest in U.S. equities, UBS' Art Cashin told CNBC on Wednesday.

Voicing a theory that he said was discussed among traders, the NYSE floor director stated that today's market highs could have been fueled mainly by overseas cash.

"Initially, futures looked like they were going to sell off and then they shot around and spiked higher," Cashin told "Squawk on the Street," suggesting that the hesitation was tied to the lack of policy details in Trump's wide-ranging address.

"That left a feeling in some of the guys who were trading that some of the initial buying may have come out of Europe, and that they were perfectly willing, since the speech was much more presidential and somewhat conciliatory, to buy into that," Cashin continued.

Responding to the argument that the speech's lack of detail was a strategy ploy to mitigate congressional resistance against Trump's policies, Cashin said it was possible, but unlikely.

"That's an interesting way to look at it, that if he didn't give you detail, that nobody can stand up and rail against it," Cashin said. "And so the absence of opposition may encourage some people. It's a bit of a stretch, but I can understand it."