What's the best way to encourage innovation?Read more
Presenter, 50 Things That Made the Modern Economy
BBC Radio 4
So if Uber is failing next to Amazon, then what does that make office property rental firm WeWork, which has seen its valuation plunge in recent months?
"If there's such a thing, WeWork would be a more extreme version of Uber, than Uber. It is losing more money, it has a worse business model, that's based on short-term loans and real estate - things that could fluctuate at any moment," Sarah Lacy, founder and editor-in-chief of the tech news website Pando told Today.
She added that WeWork is more commonly mentioned in the media for having issues with how it is run, than for anything else, which is a red flag, and that WeWork's corporate governance is "even worse" than Uber's.
In her mind, WeWork's chief executive Adam Neumann can't continue to control the board, if the firm wishes to have any chance of going public successfully.
"The company's future financing is dependent on going public this year. It has to go public this year," she said.
"What's the one dramatic thing that can change this year? That's the founder leaving the company."
BBC Radio 4
Facebook is one technology firm that managed to go public - list its share on a public stock exchange successfully - extremely successfully in fact.
But other Silicon Valley companies have had tough time selling their shares. Uber and Lyft, the taxi companies went public this year and since then their shares have tanked.
Sarah Lacy, founder and editor-in-chief of the tech news website Pando, explains the difference between Uber and Amazon, which also was a loss-maker in the beginning.
"Everyone criticised that Amazon lost money too, but if you compare the actual companies at their time of IPO, they're very different stories, and Amazon lost money until it dominated the core market, and then used that dominant position in that market, which was profitable, to then expand into other areas and invest in what it's doing," she told the Today programme.
"Uber, on the other hand, is losing more and more money quarter after quarter. Its growth is slowing, which is the big thing you cannot do if you're going to lose this much money. There is no end to this money losing in sight, and it hasn't even dominated its core market."
She adds that Uber has also "utterly failed" in its autonomous cars efforts, citing the fact that the head of Uber's self-driving project is now facing criminal charges over allegedly stealing car technology trade secrets from Google.
BBC Radio 4
As mentioned earlier, there's been big news from the US on the future of Silicon Valley - the Department of Justice (DoJ) is going to investigate large tech firms like Facebook, Google and Amazon to see if they are just too big.
The BBC's North American technology correspondent Dave Lee told BBC Radio 4's Today programme that the DoJ is looking into how market-leading platforms have achieved market power and are engaging in practices that might have reduced competition, stifled innovation, or otherwise harmed consumers.
"How did Silicon Valley companies get so big without anti-trust mechanisms kicking in?," he said.
"It could lead to some of these big companies being broken up. Facebook might be forced to separate Instagram into one company, WhatsApp into a different company, and the main Facebook app into another one."
The battle between two billionaires vying to take us to the Moon and beyond.