In early January, the first genome sequence of Sars-CoV-2 — the virus that causes COVID-19 — was released under the moniker "Wuhan-1". This string of 30,000 letters (the A, T, C and Gs of the genetic code) marked day one in the race to understand the genetics of this newly discovered coronavirus. Now, a further 100,000 coronavirus genomes sampled from COVID-19 patients in over 100 countries have joined Wuhan-1. Geneticists around the world are mining the data for answers. Where did Sars-CoV-2 come from? When did it start infecting humans? How is the virus mutating — and does it matter? Sars-CoV-2 genomics, much like the virus itself, went big and went global.