I don't have an explanation for this but I did note that the 2023 UBS report had US Median Wealth per adult at $107K[1].

I wonder if there is a per adult vs per person vs per working person difference in the measurement or something like that?

Edit: I've dug into this more, and the closest thing I can come up with for an explanation is that UBS changed its model for 2026 to "normalize household debt" in order to make it more comparable across countries. There doesn't seem to be sufficient information to explain how that change caused such a radical change.

[1]https://web.archive.org/web/20230815103944/https://www.ubs.c...