Tesla CEO Elon Musk has proposed to sell his 10 percent stake in the company. He has sought the opinion of fans on Twitter for the final decision. At current prices, Musk's 10 percent shares in Tesla would be worth about $21 billion. Some Democrats in America want billionaires to be taxed when their stock prices rise, even if they haven't sold the stock. Such tax is called unrealized gain. With a net worth of about $ 300 billion, Elon Musk is also in the purview of such rich people.