Art Cashin said the stock market has been stuck in a trading range on low volume, but a "strange parallel" to past technical conditions could indicate a major move ahead.
Cashin, UBS' director of floor operations at the NYSE, told CNBC's Bob Pisani around midday that SentimenTrader.com's Jason Goepfert has noted "we had made a 52-week weekly high on the S&P (500 stock index) and now, several days later, we've made a somewhat higher high but on negative breadth (more stocks lower than higher) for four straight days."
Cashin added, "That has happened only a few times since 1940. On some of the occasions, it has led to a selloff."
It won't take long, however, to see if history will repeat itself. "If they rally over the next couple of days, then you can forget about it. If they sell off for three or four straight days, you worry."
—By CNBC's Alex Crippen. Follow him on Twitter