Share prices of Uber's private stock have dropped about 15 percent to the mid-to-high $30s range amid a slew of bad press, The Information reported Tuesday.

The leg downward would value the privately held company at around $50 billion, down from close to $60 billion at the beginning of this year, an unnamed broker told The Information. Then, shares were in the $40 per share range, the broker said, according to the website.

Because Uber is not traded on public exchanges, it is difficult to gauge how many shares are changing hands, though another broker told The Information that transaction volumes are on the rise. Equidate, an online trading platform for large private technology companies, lists Uber's valuation at nearly $70 billion as of February. ( Equidate was not cited in The Information's report.)

Uber declined to comment to CNBC .

Uber has been notoriously protective of its shares — even big investors aren't supposed to sell them, investor Bill Maris told TechCrunch last year. Short of selling their shares back to the company itself, many start-ups offer few ways for employees to cash out. That system creates what venture capitalist Scott Kupor calls a "Faustian bargain" for many start-up employees, and it could conceivably tempt cash-poor workers to skirt the rules and sell cheap.

Still, Uber has suffered a litany of negative headlines that would have arguably dinged a publicly traded company — including an investigation into sexism allegations, a lawsuit over allegedly stolen intellectual property, and accusations of evading authorities and dodging Apple's rules.

For more on Uber's stock, see the report in The Information.