Shake Shack, the popular burger chain founded in New York City, priced its initial public offering at $21 a share late Thursday, according to a company press release. The price is above the range the company had anticipated as late as Wednesday, when it raised its expected IPO price range to $17 to $19 a share from a previous range of $14 to $16. The company, founded in 2004 by restaurateur Danny Meyer, filed for its IPO at the end of December, with the New York Stock Exchange under the symbol “SHAK.” The chain’s stock will begin trading on NYSE Friday. Also on Wednesday, the burger chain increased the number of shares it plans to sell, from 5 million shares to 5.75 million.