Which start‑ups achieve scale?

The ability of innovative start-ups to scale is a key driver of productivity and economic growth. This paper examines the factors associated with successful scaling among start-ups founded between 2000 and 2025 in the European Union (EU) and the United States (US). It distinguishes between growth-oriented firms (raising at least USD 50 million) and rising superstars (valuations above USD 1 billion), comparing their characteristics across innovation, finance, market expansion, talent, and local ecosystems. Differences in scaling outcomes relate to the timing and commercialisation of innovation (rather than inventive capacity per se), the depth of late-stage financing, and the ability to mobilise managerial capabilities and acquisitions. Scaling events are also associated with distinct ecosystem spillovers, though these depend on ecosystem depth and type of scaling event. Overall, scaling is a cumulative, selective process in which firms progressively overcome interrelated constraints, underscoring the need for stage- and ecosystem-specific scale-up policies.