As many commentators have argued, Uber and other similar services which directly connect consumers to service providers are turning a number of economic sectors on their collective heads. Given how quickly and explosively these web services have spread, their future security is all but guaranteed. Investors know this, and they will invest accordingly.
There is no doubt that Uber can raise this kind of money. They are one of the most valued tech start ups in the world right now, and investors are sure to jump on board. The real question is whether they need to raise this money after just having raised funds not long ago.
Uber might be driving the wrong way down a one way street, if they think they will be able to raise $1 billion in funding. The company has been knocking down barriers, but as they come to the new needs of financial issues, they still need to prove their service is worthy to investing in. Faced with new challenges, it's possible but unlikely the funds.
No, Uber will be unable to raise $1 billion in funding for the $40 billion valuation because of justified potential investors skittishness. Most Americans have no idea what Uber is and those that do and live outside of large cities associate it with several crimes that have been conducted by its servers.