Investors apparently have a craving for a better burger.

Hamburger chain Shake Shack Inc. has priced its initial public stock offering at $21 per share, above its proposed range of $17 to $19 per share.

It sold 5 million shares, raising $105 million. The banks managing the deal may buy 750,000 more shares.

Shake Shack cooks burgers to order and promotes its use of natural ingredients, emblematic of what's known as the "better burger" trend.

Its origins date to 2001, when Union Square Hospitality Group, a company owned by restaurateur Danny Meyer, opened a hot dog cart in Manhattan's Madison Square Park. Shake Shack now has 63 locations in nine countries.

The stock is expected to begin trading Friday on the New York Stock Exchange under the "SHAK" ticker symbol.