Just using some basic logic: Everyone wants to maximize profits, even Discover. Ergo, they see the huge bid at 9 and know people will be hitting the ask. They get hit at 10 and bid dump back to 9, rinse and repeat. They get their 100% return and it doesn't move. Once the "optimistic" few realize they are fighting a battle which they can't win, the bid support will evaporate and down it goes once again. Its has happened three times in the past year alone, but what do I know....