The winners in McDonald's 'ugly' results

McDonald's just wrapped up an "ugly month" in February, and one thing is clear: the fast food giant lost "a lot of share," one analyst told CNBC.

Despite bad weather in February, especially in New England, the overall restaurant industry posted 2.1 percent same-store sales growth, according to TDn2K's Black Box Intelligence. This marked the eight straight month of positive same-store sales.

People walk past a McDonald's restaurant, June 9, 2014, in New York.
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People walk past a McDonald's restaurant, June 9, 2014, in New York.

McDonald's failed to see this bump. Domestic comparable sales plunged 4 percent during the month, much worse than the 0.7 percent drop Wall Street had forecast, according to Consensus Metrix.

McDonald's competitor Sonic in particular has delivered blockbuster results recently, with fiscal second quarter comps rising 11.5 percent.

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"Clearly, these guys lost a lot of share," said RBC Capital Markets analyst David Palmer about McDonald's in a CNBC interview.

In a note Monday, RBC Capital Markets suggested "share losses are the result of direct competition on value including Taco Bell's $1 crunchwrap and Burger King's $1.49 10-pc chicken nugget deal (vs. McDonald's 20pc nuggets for $5)."

The firm noted the chain's domestic same-store sales deficit to its chain sandwich fast-food peer widened to -7.3 percent in February, the largest recent reading.

Despite the slide, RBC is upbeat about the stock with an "outperform" rating.

"We expect them to have some singles and doubles. Last year, they didn't even get to the plate, and certainly they didn't do so in February," Palmer said. "They just got hit hard by competitors in February."

All eyes are on the U.S., the chain's "biggest trouble spot," he added.

To turn around plunging sales, the chain is betting on menu simplification, a build-your-own sandwich platform, technology and more regional decision making. A changing of the guard with new CEO Steve Easterbrook has helped boost its stock in recent weeks.

"The valuation is compelling, and we do think the company is going to be managed better under this new management," Palmer said.

Piper Jaffray analyst Nicole Miller Regan stressed the need for McDonald's to focus on technology and its core business in a recent interview. A former long-time bull on the stock, Regan downgraded the Golden Arches to a "neutral" last week.