SAN FRANCISCO  - Snap Inc (SNAP.N) stock rose on Monday after the Snapchat owner received its first "buy" rating from a Wall Street analyst following a $3.4 billion public listing this month that raised the eyebrows of many on Wall Street.

The social media company's public listing on March 1 was the hottest by a technology firm in three years, but after two days of explosive gains, its stock has mostly fallen as investors worry about Snap's high valuation and lack of profitability.

Based on the average of analysts' buy, sell and neutral recommendations, Snap is the worst-rated stock among 288 U.S. companies that have a market capitalization of at least $20 billion, according to Thomson Reuters data.

Crespi, Hardt & Co analyst James Cakmak on Monday gave Snap its first "buy" rating and a $25 target price. Its stock at midday was up 2.09 per cent at $19.96.

"We see a company with the potential to outpace revenue growth of peers by 7x, along with a steep margin trajectory, while peer margins have likely peaked," he said in a report.

Cakmak's recommendation stands out among reports by analysts concerned about Snap's slowing user growth, widening losses and lack of voting rights for outside investors. Snap has warned it may never be profitable.

Another five analysts have recommended selling Snap while four analysts have neutral ratings.

In its first two days of trading, Snap surged 59 percent from its $17 IPO price. Since then, it has lost 26 per cent.