Sell brain-computer interfaces to people. I’m not saying that Neuralink will ever get there or that it’s a good idea but the goal is to improve on the way we communicate with computers. My guess is that Elon’s vision is some Neuralink clinics that for small price drill a hole in your skull and implant a chip. The $9B valuation is obviously just pure fantasy at this point and the $600m invested is probably from some billionaires that don’t know what to invest in anymore.