Through last Friday, the average S&P 500 stock that reporting earnings this season gained 0.04% on its report day. (For companies that report in the morning, we use that day's change. For companies that report after the close, we use the next day's change.) Below we highlight the 25 best and worst performing S&P 500 stocks on their report days. As shown, Harley-Davidson (NYSE:HOG) has had the best reaction to its earnings report, gaining 13.64% on the day. Janus Capital (NYSE:JNS) and Fifth Third Bancorp (NASDAQ:FITB) are the only other S&P 500 stocks that have gained more than 10% on their report days. Other notables on the list of earnings day winners this season include Qualcomm (NASDAQ:QCOM), Morgan Stanley (NYSE:MS), Halliburton (NYSE:HAL), UPS, Ford (NYSE:F), Pepsi (NYSE:PEP), and Schwab (NYSE:SCHW).
QLogic (NASDAQ:QLGC) has had the worst one-day reaction to earnings this season with a decline of 16.39%. SLM and Gannett (NYSE:GCI) are the only other two S&P 500 stocks that have declined more than 10% on their report days. Other big losers this earnings season include Bank of America (NYSE:BAC), Yahoo! (NASDAQ:YHOO), Google (NASDAQ:GOOG), Citigroup (NYSE:C), and General Electric (NYSE:GE).