Larry Summers has a message for Janet Yellen: Get out of the stock-picking business. At least that was the takeaway from comments made last week by the former Clinton Treasury Secretary, Obama economic adviser and wannabe Fed chairman about the current Fed chairwoman during an off-the-record meeting attended by about 100 people at the Greenwich Ct., mansion of hedge fund impresario Steve Cohen. The event, sponsored by the Stamford, Ct., Chamber of Commerce, featured a debate between Summers and Columbia University business school dean Glenn Hubbard on various issues including financial reform, Obamacare and taxes. But Summers raised some eyebrows when he took issue with Yellen’s recent biannual economic report to Congress that focused on the valuation of stocks in the social media and biotechnology sectors… Without referring to Yellen by name, he said during the debate that the Federal Reserve “shouldn’t be trying to value” various parts of the stock market, according to two people who were present. “Summers basically said it was a dumb idea to comment on subsectors of the stock market, and Hubbard agreed,” said one person who attended.