The concept born global firms has gained a spectacular increase in interest from both academic and political circles. Rigorous quantitative treatment of born global firms are however rare in the international business/economics literature. Implementing unique data on all Swedish start-ups during 1998–2008 in the manufacturing sector, we conclude that born global firms are a very rare event, that their prevalence seems invariant to time, and that they perform similar to other matched “twin” firms with regard to profitability and productivity but report a considerably higher growth in employment and sales. These results are robust to a wider definition of born global firms and to the timing of performance measurements. © 2018 Elsevier Ltd