Protests held around the world are unlikely to force change at Uber, but drivers say they are at breaking point.Read more
The drivers say the companies they work for, which include Uber and Lyft, have made it impossible to earn a living.
You might never see them, but restaurant kitchens would grind to a halt without pot washers.
BBC Radio 4
As has been mentioned, Lyft will start trading in the US later.
The ride-sharing firm does not make a profit - and neither does Uber which is expected to float soon.
Gervais Williams of Miton told BBC Radio 4's Today Programme that 30 years ago only around one-fifth of companies floating on the market were unprofitable. Now it's four-fifths.
It shows that investors are wanting to be involved in companies that are taking market shares. But, he says, he worries "they don't have sustainability".
Investors' attitudes could change quite quickly if there is a downturn.
He said he was "very surprised by how much the market has risen in the last three months".
Lyft lost $911m (£697m) in 2018 and, like Uber, shows no sign of being close to turning a profit.
The BBC's North America tech correspondent Dave Lee says - as is often the case with Silicon Valley stock market debuts - its perceived value is less about the balance sheet, and more about the hype.
Lyft is much smaller than Uber as it hasn't expanded beyond the US and Canada. But its debut will be seen as litmus test of how Wall Street feels about the long-term prospects of the gig economy.
Helen Lewis, associate editor of the New Statesman, meets Deliveroo and Uber Eats rider, Aaron Tatlow. What's it like to work for an app on your phone, when your boss is an algorithm? Some customers are very friendly, Aaron says - one man just lowers a basket for the food from his second floor window. And what about the dangers of the job, and the physical demands? Last year, Aaron cycled more than 10,000 miles delivering food to customers in York. Producer: Chris Ledgard
Is the freedom offered to workers in the 'gig economy' worth it, or does it put people at risk of exploitation? Workplaces are changing. Many are opting for short term or project-based gigs rather than structured payroll jobs: this probably includes the cab driver who drove you to work and the person delivering your lunch to your office. But this comes without a legal framework or workers’ rights. Is this freedom of work or exploitation? And what about those who don’t have another option? In this edition of WorklifeIndia, a gig worker, an employer and a professor give us their opinions Presenter: Devina Gupta Contributors: Natasha Arya, consultant bridal make-up artist Varun Khaitan, co-founder, UrbanClap Samir Kumar Singh, assistant professor of economics at Delhi University