They don't appear on the lists because their companies are usually private and hard to value because Forbes and Bloomberg et al don't even know who owns what.

They don't appear on the lists because their companies are usually private and hard to value because Forbes and Bloomberg et al don't even know who owns what. Take, for example, Jeff Yass, who didn't appear on Forbes until 2021. Well, according to the ProPublica tax leaks, he was not just a billionaire but someone who made over $1 billion in annual income(!) from 2012 upwards [1] 1 - https://www.propublica.org/article/jeff-yass-susquehanna-tiktok-tax-avoidance https://www.propublica.org/article/jeff-yass-susquehanna-tik...