According to Crunch Base Uber has debt of $22.5 billion. According to Uberpeople.net in USA, Canada and Australia Uber drivers after expenses are making less than the minimum wage. A point raised briefly n this well written book. It is most likely that Uber doesn't have a positive operating margin. And for all this they have subsidized millions of taxi rides worldwide, those who remain with Uber are quite likely price sensitive. This sets up a negative spiral that makes a successful IPO most unlikely.