Lyft Inc. shares sank 20% Tuesday on signs that competition from bigger rival Uber was stalling user growth and eating into the market share of the ride-hailing firm.

At least 14 analysts slashed their price targets on Lyft by as much as $23 after its third-quarter results, in stark contrast to the warm reception Uber received after its bumper holiday-quarter forecast.

Active riders on Lyft's platform grew just 7.2% to 20.3 million in the July-September period, the slowest pace this year and a million below market expectations. Uber, which controls a bigger chunk of the market, posted a 22% rise in active riders.

"We believe Uber has done a much better job at rebuilding driver supply, likely leaving Lyft with a structurally smaller share of the market than it had pre-pandemic," Atlantic Equities analyst James Cordwell said.

When rideshare ground to a halt during lockdowns, long-time market leader Uber's delivery business had given it an edge over pureplay Lyft.

"While we think Lyft will remain the second-largest ridehailing platform in the U.S., we are now assuming Uber will slightly increase its market share over Lyft during the next few years," Morningstar analyst Ali Mogharabi said.

Lyft's stock was at $11.51 in premarket trading. It has lost more than two-thirds of its value this year, far more than Uber's 34% decline.

However, a cost-cutting drive should help ease some of the pressure and help boost Lyft's profitability, according to Daiwa Capital Markets analyst Jairam Nathan.

The company is betting on stronger ride demand and higher service fees to offset an expected increase in insurance-related costs for the current quarter. It has also laid off employees to lower expenses.

Still, some analysts say they would rather own Uber given its scale, business model and global presence.