The has entered the third and final phase of the Dow Theory and could reach 2,600 next year, TradingAnalysis.com founder and technical analyst Todd Gordon said Thursday.
However, near-term setbacks could send the index below 2,000.
"In the near term, it feels like the markets are kind of melting up," he told CNBC's "Squawk Box," referring to a move higher in markets driven by investors who don't want to miss out on potential gains.
"I don't see the markets panicking to the topside for any particular reason, other than short covering," Gordon added.
He noted that gains in recent days have been led by the worst-performing sectors since the highs of 2015: energy, financials and materials. He said he has gone short after being long crude futures and risk-on stocks like Netflix.
"I do think there's buying opportunities, but let's get them from lower" levels, Gordon said. He further noted that a significant correction would likely follow once the S&P reached 2,600.
Katie Stockton, chief technical strategist at BTIG, told CNBC that short-term momentum has improved for the S&P, but the bounce is probably fleeting. Stocks likely won't hit new highs until later this year, she said.
"A breakout really needs confirmation, not just in price but in time," she told "Squawk Box" on Thursday. "The S&P is now testing some resistance right around 2,100, so you need to see it spend a couple weeks there to confirm a breakout, and I don't think that's going to happen."
Stockton said she is looking for a higher low relative to February's low, which could set up a washout where market metrics like breadth, sentiment and leadership reach extremes, which tend to be contrarian in nature.
"That's where I think we should actually feel comfortable buying, even though it might feel pretty terrible," she said.
— CNBC's Nia Warfield contributed to this story.