Markets can expect a 'grinding, exhausting' move lower: Pro

Several market factors suggest that stocks are on track for a gradual yet significant move lower—potentially as much as 8 percent to 10 percent, Nick Colas, managing director at ConvergEx told CNBC's "Fast Money" on Tuesday.

Colas said he had three main reasons for being bearish on the market: continued interest rate volatility, ETF outflows and declining earnings estimates. "That puts a pin in the bubble notion that valuations continue to be cheap."

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These conditions could result in an 8 percent to 10 percent move lower for stocks—a "grinding, kind of exhausting move to the downside over the course of a month or six weeks," he said. "We're not going to get any one-day event that really pushes us down. It's going to be a slow grind, which feels very painful when it's happening."

Despite calling the CBOE Volatility Index a "flawed indicator," Colas said that it's important for investors to keep in mind as a gauge of investor sentiment, and if the VIX moves over 20, "it's definitely time to take a look" and expect larger moves.

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The biggest losers will likely be consumer-related sectors, such as retail, he said, although car companies are likely to continue their relative strength.

"The financials are the big tell in the market," Colas said. "Whenever they bottom and however they bottom, that's when you're going to see the market bottom."

When asked if he would short the market now, he was hesitant, because there is no single catalyst set to cause a sell-off.

"This is more about the market trending downward versus saying you've got to get out and get short here," he said. "Valuations aren't stupid, they are just, I think, full."

— By CNBC's Paul Toscano. Follow him on Twitter @ToscanoPaul