After the US government outlined a plan to change the way workers are treated, shares in some of the world's largest gig economy companies fell.
Workers would be more likely to be classified as employees under the proposal.
The news caused shares in firms to fall.
Millions of people are working in the global gig economy.
The rule would try to stop companies from misclassifying workers.
Many cases of employers misclassifying their employees as independent contractors have been seen by his department.
Workers are deprived of their federal labour protections, including their right to be paid their full, legally earned wages, if they are misclassified.
The public consultation on the proposal is scheduled to last 45 days.
In New York, the shares of each of the three companies ended down.
The plan was a clear blow to the gig economy and a near-term concern for the likes of ride hailing companies.
"With ride sharing and other gig economy players depending on the contractor business model, a classification to employees would essentially throw the business model upside down and cause some major structural changes."
The three companies did not reply to the requests for comment.
Gig economy firms have become more scrutinized as the industry has grown.
According to Mastercard, 78 million people will be employed in the gig economy by the year 2020.
Gig workers don't get a regular wage because they are paid for individual tasks.
Federal and state labour laws do not apply to gig workers.
The Supreme Court of the UK ruled in favor of the drivers of the ride-sharing service.
Two former drivers argued that they should be paid the minimum wage.
They took the company to an employment tribunal.
The ruling centered on a small group of drivers and the company has made changes to its business.