After a positive open, stocks suffered a sharp intraday slide on Thursday that saw the Dow Jones industrial Average drop by more than 200 points. Now traders will have to closely watch the next few sessions to learn whether the five-year bull market might finally be coming to an end, according to UBS' director of floor operations, Art Cashin.
"I don't know about the bubble bursting, but we've done some serious technical damage," Cashin said on Thursday's episode of "Futures Now." "The next several days will be absolutely critical. If we see continued weakness, you will begin to hear people talking about having put the top in."
In explaining the weakness on Thursday, Cashin turned to rumors about the volatile situation in Ukraine.
"Early in the day, when we tried to rally, the S&P ran into some very strong resistance at 1,878, 1,874. We began to pull back very slightly from there. Then the rumor wires went hot with a lot of vague rumors about Ukraine and Crimea—rumors about statements that hostility was growing nearer, further rumor about possible shots being fired. Now, none of that was confirmed, but it was enough to spook the market," Cashin said.
On Sunday, a referendum vote is scheduled to be held in Crimea, in an apparent Russian attempt to make the Ukrainian republic a part of Russia. Cashin says the fast-moving situation could end up having a big impact on financial markets, especially if it leads to sanctions against Russia.
"If they have to wind up putting in heavy sanctions, Iranian-type sanctions on Russia—which I think is unlikely—that would have very negative financial implications around the world," Cashin said. "It would hurt global growth."