He collected hundreds of millions in payments for the new Roadster that was supposed to be delivered years ago, but there is still no sign of it. He has been promising full self driving next year for a number of years too, but he is actually behind other manufacturers in this space now. He claimed range figures for his HGV that were unrealistic and "demonstrated" it with a load a tenth of what an HGV usually carries.
The value of the company will probably double as you suggest, but because of the gullibility of people falling for his grifts rather than any track record of success.
Edit: I forgot his promised ROI on his self driving taxis that would make it pretty much the best investment opportunity in the world, outpacing the stock market by multiple orders of magnitude.
