You could call it a valentine to the market.
MacNeil Curry, the head of global technical strategy at Bank of America Merrill Lynch, was bearish on the S&P 500 going into 2014. But now he says it's time to buy.
"Up until yesterday we had been bearish risk assets and the S&P 500," Curry said in a Friday note. "Yesterday's close above 1,823 says that view is WRONG and that the larger uptrend has resumed," he wrote.
The technician now holds that the recent strength in the S&P 500 "should project further upside for a test of the highs at 1,850—and perhaps on up to the long-term channel at 1,872."
What persuaded him to get bullish is the recent strength in the S&P, which has bounced nearly 6 percent off its lows Feb. 5.
"The setup was pretty bearish, frankly," Curry told CNBC.com. "We had the impulse of decline from the highs of 1,850, fairly negative seasonals, and a pretty sharp deterioration of breath. With all of that, I was pretty confident we would head lower and probably take a run at 1,711. ... That we've then reversed as hard as we have and started to trade quite bullishly says I'm wrong."
Earlier this week, he told CNBC.com that he noticed "breadth deterioration" in the market, "which is often what you see in a correction." He went on to note, however, that "if we close above 1,823, then things start to get more constructive."
The rebound "was really frustrating," he said. "But this is the nature of the biz. You get everything aligned and you take your shot. And you figure out where you're wrong when you're wrong, and move on."
(Read more: Byron Wien expects 20 percent gain for S&P 500)