John Curtius over the last two years became synonymous with the most disruptive force in venture capital—Tiger Global Management.

The news that he will start his own startup investment fund next year throws the future of Tiger’s tech investing into question. During Curtius’ tenure, the hedge fund turned startup investor poured more than $10 billion into hundreds of private tech companies, fueling investor competition that lifted valuations to levels that now look inflated. He has pushed the firm—best known for bigger bets in mature companies such as Roblox and Coinbase before they went public—to invest in younger, Series A– and B–stage startups where they can buy larger stakes for less. That ruffled the feathers of longtime Silicon Valley investors who suddenly had to contend with another big-pocketed rival.

While Curtius (pronounced “KURT-us”) has agreed to stay at Tiger until next year, a startup founder of a company who previously raised capital from him told The Information on Monday that the departure means founders in Tiger’s portfolio will be anxious about whether they can count on future investments from the firm should they need them. (Update: Curtius abruptly exited the firm on Oct. 6, contrary to the previously announced timeline.)