Biotech, Social Media Stocks Are Less Frothy Than Janet Yellen Thinks

NEW YORK (TheStreet) -- A month after Federal Reserve Chair Janet Yellen said they were overvalued, Internet and biotech stocks continue to push to new highs. Both the First Trust Dow Jones Internet Index and SPDR S&P Biotech exchange-traded funds led markets higher Wednesday, fueled by the better-than-expected earnings season and improving outlooks.