Billionaire tech titan Elon Musk may be working to build multiplanetary civilization, but he's also peddling hats. A whole lot of them, too.

The Tesla and SpaceX boss said Sunday night he had sold 30,000 hats promoting his tunneling venture, The Boring Company. At $20 a pop, that means Musk has brought in $600,000 — from selling hats.

https://twitter.com/elonmusk/status/940055330859315202

Last week, Musk said he would cap sales at 50,000 hats. If he reaches that milestone, Musk will have been able to bring in $1 million by selling hats. (He also changed his Twitter bio to "Hat Salesman.")