True, the actual outcomes and probabilities are complicated, and there are many success scenarios where uber doesn't yield a trillion dollar market cap. I was b

True, the actual outcomes and probabilities are complicated, and there are many success scenarios where uber doesn't yield a trillion dollar market cap. I was being simplistic, to demonstrate the principle. Apple, Amazon & Apple are headed towards that trillion now, so I think this is a possibility, and possibilities drive investment. If the stock market itself stays good, it is almost inevitable one of the three will tip that number soon. Once one does, I'd expect a half dozen within a decade. On the taxi market cap... This is an interesting one. I agree that uber had their eye on more/bigger opportunities (especially self driving), but ignoring that... The market cap of an industry is not only related to its size. It's related to the margins, lock-in and other attributes of the companies operating within it. Also, debt & capital efficiency. A more competitive market may have lower market caps, because margins are thinner and companies can fail. IE, while market cap of the industry might be Y, "an uber" dominating that industry might still achieve a market cap of 5Y.