Elon Musk's tunnel-building venture, the Boring Company, is reportedly closing in on a funding round that could quadruple its valuation to $20 billion. The Wall Street Journal, citing sources familiar with the negotiations, reported that the startup seeks approximately $4 billion in fresh capital. Main Developments According to the report, the funding talks remain fluid—terms could still shift before the round closes. Neither the Boring Company nor Musk's other firms have officially confirmed the valuation or the investment amount. Reuters noted it could not independently verify the WSJ report. The Boring Company did not respond to requests for comment outside regular business hours. Read also: 3 ways overdue dues strain Pakistan's energy supply chain Background Founded by Musk—whose portfolio also includes Tesla, SpaceX, and Neuralink—the Boring Company develops tunneling technology and low-pressure tube transport systems for passenger pods between cities. Its last major fundraising in 2022 netted $675 million at a $5.7 billion valuation. The company's flagship operational project is the Vegas Loop in Las Vegas, Nevada, which began carrying passengers in 2021. The system now connects eight stations and has transported more than 3 million riders, according to the company's website. Why It Matters A $20 billion valuation would mark a dramatic leap for a startup that, while still unprofitable, has proven its concept can move people at scale. The raise signals strong investor appetite for infrastructure ventures tied to Musk's brand, even amid broader economic uncertainty. For urban transit observers, the company's progress—or lack thereof—on intercity projects will be a key test of whether its technology can scale beyond Las Vegas. What's Next The funding round has not yet closed, leaving the final valuation and investment amount subject to change. If completed, the cash injection would likely accelerate expansion of the Vegas Loop and fund new tunneling projects in other cities. Open questions remain about timelines for any intercity routes Musk has previously pitched, including a Washington-to-New York link.