If he sold 10,000 shares he'd get 3,300,000 in proceeds and owe something like 660,000 in LTCG taxes. So lets say FB shares are $330 today and Zucks basis on them is for all intents $0. He can trade those on greater than 1 year cycles to make them long term gains. He then invests the money in something else to 'diversify' when he does this this cost basis there will be the current price of the securities, not zero like his FB holdings. He will pay interest on the loan of course and also on the entire principle amount but at a much lower rate than even long term capital gains taxes in our current environment.
Zuck could for example take a personal loan against facebook shares (pays no taxes), avoids what would be huge capital gains exposure on his founders stock. This is correct in the top line sense but in terms of individual wealth building its 'more complicated'
