Each new Y Combinator class worth more than a billion dollars, president says

Well, if that's true, YC is making 12X return on their investment on average per startup. If we assume average exits as 5 years, this would be equivalent to more than 2X return per year per startup. Either we are in bubble, or YC is the best investment vehicle human kind has invented, or there is lot of smoke and mirrors. Either way, interesting times...