Elon Musk's tunnel-digging venture the Boring Co. raised $112.5 million in a recent funding round, according to a document filed Monday with the U.S. Securities and Exchange Commission.
Most of the money — more than 90% — came from Musk himself. The rest was from "early employees" of the company, according to the Boring Co.
The company said no venture capitalists or outside investors were involved in this round.
The funding round is a more conventional method of fundraising than Musk's most recent money-maker — sales of flamethrowers. Musk, who is also chief executive of SpaceX and Tesla Inc., said in January that the Boring Co. had pre-sold 10,000 flamethrowers branded with the company logo for $500 apiece. He also said at the time that he sold about 3,000 fire extinguishers for $30 each.
The flamethrower and fire extinguisher sales came after a similar, though less flashy, fundraiser by Musk to sell 50,000 Boring Co. branded hats for $20 each.
The Boring Co. has said its goal is to increase the speed and lower the price of digging tunnels to reduce traffic congestion.
The company has already dug a tunnel across from SpaceX's headquarters with a boring machine it purchased. Last month, Musk said the company's tunnels and Hyperloop plans would prioritize pedestrians and cyclists over cars. Passengers would load into a pod with large windows that's lowered underground before it speeds on a track, according to a video Musk tweeted in March.
"Will still transport cars, but only after all personalized mass transit needs are met," Musk tweeted Mar. 9. "It's a matter of courtesy & fairness. If someone can't afford a car, they should go first."