Uber the largest Taxi company, with no taxis could become the 

Most valuable Start-up ever in business history.

What to learn more, read the following articles:

Business Insider (09/05/15)

Uber said to be raising $2 billion, could soon be the most valuable startup of all time at over $50 billion.
By Matt Weinberger

Wall-Street Journal (09/05/15)

Uber Eyes $50 Billion Valuation in New Funding

By Douglas MacMillion & Telis Demos