Here's an example: http://m.bbc.co.uk/news/business-27058146 http://m.bbc.co.uk/news/business-27058146 Google's share price changes the same day as an announce

Here's an example: http://m.bbc.co.uk/news/business-27058146 http://m.bbc.co.uk/news/business-27058146 Google's share price changes the same day as an announcement. The BBC attributes the change to the news as though they are monotonic. But who is to say that the news didn't stop the share price falling twice was far? Also, every trade requires two parties, so one side thought they were getting a good deal. I'm also amused that the share traders are called "investors" rather than "gamblers".