Art Cashin, UBS director of floor operations at the NYSE, said several factors are hurting stocks: Geopolitical tensions, Ebola worries, deflation and growth concerns.
"We started out a little weak," Cashin noted. "There was a support band in the S&P at 1,962-1,965. Once they [stocks] broke through that, the selling accelerated."
Economic data this week has been disappointing in the U.S. and across the pond. Europe finished lower after a report showed manufacturing slowed further in September as new orders decreased amid falling demand at home and abroad. In the U.S., there was a triple whammy of poor data Wednesday: A manufacturing gauge, construction spending and auto sales all came in lighter-than-anticipated. That's on top of worse-than-expected pending home sales, S&P/Case-Shiller data, Chicago PMI and consumer confidence reports out Monday and Tuesday.
Traders took a flight-to-safety approach early in the session with bonds, gold, oil and the U.S. dollar all rising. The 10-year Treasury yield fell to a one-month low and the dollar continued its climb, reaching another four-year high.
"That tells you people are a little nervous about stuff," Cashin said.
The S&P 500 is down more than 1 percent, sitting nearly 4 percent below its record. Among the biggest losers are airlines, hotels, resorts and cruise lines amid fears there may be more Ebola victims in the U.S.
Air carriers, like Delta Air Lines and Southwest Airlines, are tumbling 3 percent as there is speculation people may restrict flying and travel in general. That's dragging down Royal Caribbean Cruises and Starwood Hotels too.
Friday's jobs report and Thursday's European Central Bank (ECB) policy decision and press conference are on traders' radars.
According to Cashin, the jobs report is likely to be a Goldilocks number.
"If it's too good, if it's closer to 300,000, it might spike some of the bond vigilantes and get them kicking in," he said. "If it's too low again, you'll get people saying 'wait a minute, the Fed might have credibility problems here' because do they come back with another QE?"
Just as the U.S. is set to scale back its easy money policy, Europe is slated to do whatever it takes to restore the region that is struggling to grow and dealing with ultra-low inflation.
"I think [ECB] expectations are too high," Cashin noted. "I think he's [ECB head Mario Draghi] going to disappoint."
The ECB decision is released Thursday at 7:45 a.m. EDT, followed by Draghi's press conference at 8:30 a.m. EDT. Friday's jobs report is out at 8:30 a.m. EDT.