Earnings season started 8 days ago when Alcoa (NYSE:AA) reported earnings, and so far only 78 US companies have reported their quarterly numbers. The average one-day change in response to these 78 earnings reports has been positive at +0.22%. Below we highlight the 20 stocks that have gone up the most on their report days this earnings season, and the 20 that have gone down the most. As shown, Supervalu (NYSE:SVU) is currently the earnings season leader with a gain of 16.85% on its report day. Titan Machinery (NASDAQ:TITN) and Knoll (NYSE:KNL) are the only other stocks that have gained more than 10% on their report days.