Geoff Huston has published an excellent report on the state of #IPv4 and #IPv6 through the course of 2025:

https://www.potaroo.net/ispcol/2026-01/addr2025.html

It is very much worth reading through if this is something you're involved in. It covers topics including where we've landed with IPv4-per-capita for various countries (and associated inequality) as well as how the IPv4 transfer market pricing has substantially softened over the course of 2025.