Art Cashin said technical factors are helping to deepen the stock market's downward move today.
Cashin, UBS' director of floor operations at the NYSE, told CNBC's Bob Pisani, "The S&P had stopped at 1770 every time it got down there and then bounced... So the minute they went to 1770 and failed to hold a spiral (was) produced and we went down... We got down to about 1760. They tried to rally at that point and the rally got stopped dead at 1770 under the old rule that broken support often becomes instant resistance."
The S&P closed Monday at 1741.89, down 40.70, or 2.3 percent on the day.
Cashin also urged viewers to carefully watch the yield on the 10-year U.S. note. "It's very close to breaking 2.6 percent. So there's more here than just the stock market technicals. That's a good sign that there's trouble again in the emerging currencies."
When asked by Pisani if there's concern about bad weather negatively affecting Friday's data from the government on January employment, Cashin replied, "I think these guys have decided they're going to use weather as a 'get out of jail free' card."
He's heard of traders planning to come to trade Friday "on the assumption you're either going to get a better number, or if you get a lousy number, it will be excused away because of the weather."