Pro: Prepare Yourself For An Imminent 'Nasty' Market Drop

Tony Dwyer is the senior managing director and chief market strategist at Canaccord Genuity and is generally bullish on stocks. Speaking as a guest on CNBC's "Trading Nation," he explained why his bullish stance no longer applies.

Dwyer argued that the market is historically overbought as evidenced by the relatively high percentage of S&P 500 stocks that are trading above their respective 10-, 50- and 200-day moving averages.

Expect The Correction

Dwyer continued that it has now been 146 days since there has been a correction of at least 5 percent. This happens to be the second longest streak without a notable correction and the record stands at 158 days in 2015, so naturally the current market is "bumping up" against the longest cycle.

"So, it's kind of a combination of all these things that creates an environment that's ripe for just kind of a nasty little pullback," Dwyer said.

Dwyer suggested that the market could be due for a correction of at least 4 percent and up to 7 percent even though the fundamental backdrop remains strong. In fact, the market correction would likely come from an unpredictable news item that investors won't see coming.

There is, however, some good news in Dwyer's outlook. Following the pullback, investors are encouraged to jump right back in as the next leg of growth in the market will be "significant."