I'm not sure I agree with your "bought stock in your job" example.
A better analogy would be:
- your performance is great
- your boss tells you that you'll get a promotion next year if you keep it up
- your performance takes a turn for the worse
- your boss tells you your performance is worse and lets you know that the promotion next isn't a sure thing
The stock market is a market that allows people to buy and sell stock at the price they see fit. The market should reflect all available information. I don't see any reason why LinkedIn's stock shouldn't plummet if suddenly their growth prospects went from "spectacular" to "so-so".
A better analogy would be: - your performance is great - your boss tells you that you'll get a promotion next year if you keep it up - your performance takes a turn for the worse - your boss tells you your performance is worse and lets you know that the promotion next isn't a sure thing
The stock market is a market that allows people to buy and sell stock at the price they see fit. The market should reflect all available information. I don't see any reason why LinkedIn's stock shouldn't plummet if suddenly their growth prospects went from "spectacular" to "so-so".