Microsoft could help Facebook with one of the biggest challenges, namely monetizing its traffic without reducing the user's experience. It's obvious that Microsoft needs traffic and Facebook needs search.

Microsoft has one more shot at a role in smart phone software through its deployment on Nokia phones. Nokia is still the global market share leader in cell phones. Maybe it will work out, but this is hard to envision great success in the area coming on the heels of so much disappointment in missed opportunity in this important and visible category.

One of the best investors around, Joel Greenblatt, has written a popular, charming and funny book about investing in great companies at low P/E multiples. To simplify an already simple book, great companies are generally measured as companies that can generate lots of profit without requiring a lot of capital. This means that they have high ROEs.

In the real world, illiquid assets carry a discount.

When people ask me what I do for a living, I generally tell them 'I run a hedge fund.' The majority give me a strange look, so I quickly add, 'I am a money manager.' When the strange look persists, as it often does, I correct it to simply, 'I'm an investor.' Everyone knows what that is.

What is uncertain is how much further the bubble can expand, and what might pop it.

You have a certain set of facts and you are looking for situations where you have an edge, whether the edge is psychological or statistical.