The original offering for the shares was between $9 and $11, but shares ended up opening at $28.66. In the first few minutes of trading, the price jumped more than 125 percent to $31 per share.
The company sold 7,362,166 shares of its common stock. Selling stockholders will sell the remaining IPO shares.
Potbelly will not receive any sale proceeds from the remaining stockholders. The underwriters of the IPO, including Bank of America, Merrill Lynch, Goldman Sachs, R.W. Baird, William Blair and Piper Jaffray, have a 30-day option to purchase another 1.125 million shares.
Potbelly operates 288 shops in 18 states and D.C., with seven more operated by franchisees. Twelve more franchises are operated in the Middle East.
By 10:30 a.m., 8 million shares have sold, and stocks have jumped all the way to $32.25.