On a wretched day for stocks, the CBOE Volatility Index (or the VIX) jumped 22 percent on Thursday, which likely indicates that investors are growing increasingly concerned about the market's next move. And if fears on Wall Street are correct, then stocks may suffer through an especially difficult few weeks.
"After a long and low period of implied volatility across the board, you are seeing some realization that maybe it is time to buy volatility and maybe get more conscious on risk assets like stocks," said Nicholas Colas, chief market strategist at ConvergEx, on CNBC's "Futures Now." "Clearly there has been a rising level of concern among institutional investors about the market feeling toppy. We've heard that from our clients, and we've seen it from the action on our trading and options desks."
He said that seasonal trends point strongly to a spooky October.
"Right now the VIX high for the year was in February: 21.44 on February 3. If you go back 25 years to the beginning of the VIX, it's never topped out in February. October is typically a very high volatility month," Colas said on Thursday.
"I do expect that we get a pullback that rolls through the first half of October. It's seasonally right. We've had a lot of complacency. There are enough headlines to concern people. And let's face it—stocks may not be expensive, but they're not cheap either," he continued.