Why Elon Musk will end up with an $11 billion tax bill this year

Elon Musk says his tax bill this year will be $11 billion, and he's probably right: The filings he has made with the Securities and Exchange Commission about his recent stock trades back up that massive number.

Musk revealed the $11 billion total in a tweet Sunday that was otherwise short on details.

This is not significantly different from what he had tweeted last week when, in the midst of a Twitter war with Sen. Elizabeth Warren, he said he'd pay the largest individual tax bill in history this year.