Closely followed trader Art Cashin told CNBC on Tuesday that Wall Street could be "in a bit of trouble" if tech stocks fail to rebound soon.
"The reversal yesterday was a bit ugly. There were various rumors around it. Some even tried to attribute it to the Supreme Court allowing the president's travel ban," UBS' director of floor operations at the New York Stock Exchange said on "Squawk on the Street."
Cashin said there were worries on Wall Street this week that President Donald Trump's travel ban would make it difficult for some to obtain work visas in the U.S. The Supreme Court on Monday agreed to allow parts of the ban to go into effect and will hear arguments in the case.
U.S. stocks opened mostly lower Tuesday after news that the European Union fined Google for violating antitrust rules. The Nasdaq underperformed, falling modestly shortly after the open. The Dow also slipped, with Apple contributing the most losses.
Large-cap technology stocks dropped Monday, but the tech sector has outperformed in 2017 has gained nearly 20 percent year to date.
Regarding the Federal Reserve, Cashin said investors should keep an eye out for market moves after Chair Janet Yellen's speech on Tuesday at an event in London at 1 p.m. ET.
Cashin also said he believes the market hasn't bought into the fear that the Trump administration can't get its agenda done. Cashin said perhaps the bigger story on Tuesday is comments by Mario Draghi, president of the European Central Bank.
At the ECB forum in Sintra, Portugal, on Tuesday, Draghi spoke on "strengthening and broadening recovery" in the euro zone.
"He said the threat of deflation is dead," Cashin said. "And that sparked an instant rally in the euro and raised yields in Europe quite smartly. And even raised yields here."
— CNBC's Fred Imbert contributed to this report.