This paper identifies export accelerations at the country pair-product level that are large enough to drive aggregate export growth in the medium run. In a sample of 100 countries, these export “big hits” are rare, less than 2 percent of all export spells, yet account for over two-thirds of export growth in a given country. The paper then explores their microfoundations using matched customs-census firm-level data for France. We find that typically, two firms are sufficient to generate a big hit and these firms’ access to external financing is key to their ability to drive export success. Moreover, big hits spread within firms across destinations and products. Our results offer new evidence on the granularity of export growth by linking micro-level entrepreneurial decisions with country-level export outcomes.