The real reason behind Musk's share sale: there are still nearly $100 billion in option taxes to pay

Nov. 8,In the next few months, Tesla (TSLA.O) CEO Musk will face a stock options tax bill of more than $15 billion. He is likely to sell Tesla stock this year regardless of the outcome of the vote on Twitter. Musk received 22.8 million shares of stock awards in 2012 with an exercise price of $6.24 per share. Based on Tesla's closing price of $1,222.09 on Friday, Musk earned just under $28 billion through those options. By calculating that the total federal tax rate plus California state taxes would be 54.1%, Musk would have to pay $15 billion in taxes on these options. Musk is likely to sell his stock at least two quarters apart due to the limited window for CEO-level executives to sell their stock.