U.S. stocks made a strong comeback at Friday's midday trading from Thursday’s losses. The Dow Jones Industrial rose nearly 190 points. The Nasdaq is trading above the key psychological mark of 5,000. Biogen (BIIB) helped to boost the Nasdaq. The stock was the best performer on the S&P 500 after detailing successful results from its experimental drug for Alzheimer’s disease. Earnings were a big driver in the session. KB Home (KBH) jumped more than 7% after topping expectations on both the top and bottom lines. Darden Restaurants (DRI) was another gainer on the back of strong quarterly results. The restaurant chain operator reported a rise in same-store sales and boosted its full year outlook.