Though still a cool billion short of ANT Financial's $4.5b Series B in April, Saudi Arabia's Public Investment Fund's $3.5b investment in Uber raised a number of eyebrows.

Some have pointed to its significance as an indicator of the reduced importance of public markets for technology firms (Uber has now raised $11b from private investors). 

Others are pointing to the potential damage that this fundraising could have. On-demand rides are just one area where cash is being ploughed into discounts to ensure market share capture. And while low prices mean that consumers win in the short term, what it means in the long-run is unclear as Uber is clearly aiming for complete control of its market, and investors will eventually want to see returns.