Uber wants to own the robotaxi era without building the cars. “Building a great autonomous driver is one part of building a successful autonomous business,” chief executive Dara Khosrowshahi told analysts on Wednesday. He then listed the rest: dispatch, fleet operations, charging, insurance and regulators. It is a bet the company is spending billions to defend, and one the market is not yet sold on.

On paper, the quarter was strong. Revenue rose 12% to $14.2bn and gross bookings jumped 24% to $58bn. Uber also generated more than $10bn of trailing free cash flow for the first time, it said, and signed up more first-time users than in any period in five years. Yet the stock fell as much as 6%, its worst day in six months, Bloomberg reported.

The immediate trigger was the outlook. Uber guided third-quarter bookings to a midpoint near $59.25bn, just shy of the $59.33bn analysts wanted. Its profit forecast landed below estimates too, CNBC reported. Trip growth also slowed, which Uber blamed “entirely” on Brazil, where the Chinese rivals Didi and Meituan are spending hard on deliveries.

The one question Uber keeps getting asked

None of that explains why the stock is down 12% this year. The real worry is robotaxis. Uber built its business on human drivers, and self-driving cars threaten to route around it. Its answer is to become the platform every robotaxi operator plugs into, rather than build the technology itself, and it is paying to hold that ground.