Stocks may be slipping, but investors shouldn't ditch their holdings just yet, according to a new report from Fundstrat Global Advisors technical strategist Robert Sluymer.

That's because, according to Sluymer, they've been falling for three months already.

"I think the really key point here is that most stocks have been correcting since the middle of December. If you think about where the yield curve peaked, where the breakevens [peaked], where oil [peaked], where the relative performance of the Russell 2000 peaked, that was already three months ago," Sluymer said Monday in an interview on CNBC's "Trading Nation."

After its worst week of the year, the in Monday trading logged its seventh negative session in eight, falling as low as 2,322.49 as it dipped below its 50-day moving average for the first time since Nov. 9. Sluymer sees the market pulling back to its 100-day moving average, around the 2,275 mark. And when it comes to the "worst-case scenario," he sees more downside, around the 200-day moving average (implying more than 5 percent of downside from current levels).

"But I don't think it's reason enough to get negative long term. I think what's happening is you're setting up for some very good buying opportunities as you move into the second quarter," he said.

Indeed, heading into a heavier period of earnings, Sluymer said much of equities' overbought condition developed going into the end of the year will be "unwound," but will present a buying opportunity, he said.

What's more is the so-called "reflation trade" many investors saw as kicking off in November actually began in the beginning of 2016, according to Sluymer.

"So those themes continue, and they're already correcting. So, again, I think as we move back into earnings season, I think there's going to be a much better opportunity to be looking at some stocks, and that's only a few weeks away," he said.

