Why do we care? Are we becoming Wall Street traders and "analysts"? What use is reporting or reading about stock movements within a day?
In case you're not actually trolling, here is why. Because a change in market price reflects a change in the midpoint of opinion of people on the future value of Facebook, who are willing to put their money where their mouth is with regards to their opinion -- these are not the opinions of idle chatterboxes. As such, stock price movement in response to news is a very valuable critique of a company's actions. A change…
Surely not THEIR money. Someone else's money, with a fee for "expenses"