Digital watermark company Digimarc Corp saw its shares jump as much as 340% on the Nasdaq Thursday after an $80m initial public offering. The Tualatin, Oregon-based company sold 4 million shares at $20 each. The stock opened at $84 and traded up to $88 before closing at $56.625 for a 183% first-day gain. Total volume for the day was 6.38 million shares.

As a result of strong demand, the size of the offering was increased Wednesday from an initial total of 3 million shares and the price range was raised from $13-$15 to $16-$18 – still well below their eventual selling price. Robertson Stephens, Hambrecht & Quist and U.S. Bancorp Piper Jaffray Inc., are the managing underwriters of the offering.

In the nine months ended September 30, Digimarc showed a net loss of $824,000 on revenues of $4.2m. Last year, it lost $3.4m on revenue of $984,000. The company said it will have 11.9 million shares outstanding after the IPO, giving it a market capitalization of roughly $674m, based on Thursday’s closing price.