Investors can’t get enough of Elon Musk Inc.

The Boring Company, the tunneling company Musk founded with the aim of “defeating traffic,” announced on Thursday it had raised $3 billion in a funding round that values the startup at $23 billion.

It’s the latest major injection of cash into Musk’s business empire, after SpaceX raised $86 billion in a record-breaking public listing in June.

Investors have continued to clamor for a piece of anything Musk-related. Business Insider previously reported that Neuralink, the billionaire’s brain implant startup, was being valued as high as $42 billion on secondary markets, nearly five times the $9 billion…