I agree that there is a parallel but the difference is very real. While both Bill and Mark have their net worth based on their assets only Bill could actually s

I agree that there is a parallel but the difference is very real. While both Bill and Mark have their net worth based on their assets only Bill could actually sell those assets today to achieve that net worth. Also, as you mentioned, Microsoft is traded nearly every second so the value of each of Bill's shares are infinitely closer to their actual value. Zuckerberg's net worth is based off the inflation that Facebook's shares have received after the latest round of investment. He doesn't have the option to sell those assets and as such shouldn't be able to count that as his net worth. I highly doubt that Mark Zuckerberg could sell his shares of Facebook for $1.5 billion right now. I also doubt that had that latest round of financing happened this week that it would have valued the company so high. To place someone on a list as the 'Youngest Billionaire in the World' when he actually has only the chance at $1.5 billion is a mis-understanding. Therefore the term Zuckerbucks should be used to state what his net worth COULD become if he is able to reach a liquidly event.