Generac Holdings Inc., Waukesha, Wis., parent company of generator manufacturer Generac Power Systems, Inc., has priced its initial public offering of 18,750,000 shares of common stock at $13 per share. The shares began trading on The New York Stock Exchange on Feb. 11 under the ticker symbol “GNRC.” In addition, Generac Holdings Inc. has granted the underwriters a 30-day option to purchase up to an additional 2,812,500 shares at the initial public offering price. News reports said the company had hoped to raise $335 million through the IPO, but raised an estimated $244.4 million after it had to lower its price to $15 from the $17 per share it had initally wanted.