Grading Janet Yellen's social media bubble call By: CNBC.com News August 12, 2014 at 07:00 AM EDT The Fed Chair has made a career of predicting interest rates, but when it comes to stock calls-her newest vocation-she's off to an uncertain start. Read More >> Related Stocks: Facebook Fairfax Financial Hldngs Pref Ser G GX Social Media ETF Google, Inc. Groupon Cl A Nasdaq Biotechnology Ishares ETF Netflix Oracle Corp Pandora Media Inc S&P Biotech SPDR T.Rowe Price Group TripAdvisor Twitter, Inc. Yahoo Yelp Inc Zynga Inc Cl A