Rumors swirled that the NASDAQ was about to lower the weighting of Apple (AAPL) shares currently at 20% of the index ($NDX) related to the QQQs. The exchange didn't comment when asked but this weighting existed for a long period prior it being reduced just last year I believe. This caused a sharp $30 reversal in Apple's price. Generally, technicians dub this an "outside day" when the stock opens much higher and then reverses closing near the day's low. This is bearish technically. It shouldn't surprise anyone if this rumor was planted by shorts.