1) If you believe FB will be worth $140+ billion in a few years, but you want money now/have a fund coming due it might make sense to sell at $70 billion. 2) I

1) If you believe FB will be worth $140+ billion in a few years, but you want money now/have a fund coming due it might make sense to sell at $70 billion. 2) If you believe FB will be worth $140+ billion in a few years, and can afford to wait it might make sense to buy at $70 billion.