Qualcomm Inc QCOM.O and Roku Inc ROKU.O tumbled 8.1% and 15.1%, respectively, after their holiday quarter forecasts fell below expectations. By Shubham Batra and Amruta Khandekar Nov 3 (Reuters) - U.S. stocks extended losses on Thursday as investors feared the Federal Reserve was far from signaling a less hawkish stance in its fight against inflation. Stocks initially received a boost on Wednesday after the Fed raised interest rates by 75 basis points as expected and the policy announcement left open the possibility of smaller increments in the future.