Alexandre de Rochefort, CFO for major mobile phone developer Gameloft, says inflated private and stock market valuations for social gaming companies are causing an unsustainable bubble to develop. Speaking at the Reuters Global Technology Summit, de Rochefort said he has resisted calls to move his company from Paris' Bourse exchange to the American NASDAQ, despite a likely stock price bump, because he thinks any such inflated prices in the U.S. market won't last. "I am sorry but when Zynga is worth $10 billion something is a bit strange," he said, as reported by Reuters. "If this is not a bubble, I don't know what is." De Rochefort also used the summit to highlight Gameloft's continuing focus on hardcore gamers, saying the company would not follow the wider trend towards casual games targeted at new audiences. "Zynga has made it very clear that their typical client is a female, 40 years old, staying at home in the mid-West," Rochefort told Reuters. "Gameloft has not sold a single game to this kind of client in the last 11 years." Despite 2010 revenue growth that was largely driven by iOS sales, de Rochefort also highlighted Gameloft's continued success in the declining feature phone market, which feature less competition because of higher barriers to entry, he said. Gameloft recently posted job openings for a new New Orleans studio as the company looks to expand to TV games and Amazon's Android marketplace.