Ok, so I guess it makes sense that the price would drop a lot since near term profits should be weighted more heavily than long term. 10% still seems like a lot with exponential discounting unless this is going to hit a lot harder and longer than I expect.
Well... What I said is kind of the ideal world. The reasonable value of the stock is the time-discounted expectation of future profits. The actual value is heavily influenced by what each person thinks everyone else thinks. So for the price to drop, people don't have to think it will affect future profits at all. They just have to think that other people will think that the price should drop.