According to this wikipedia page - Median wealth per adult globally is estimated at $8,654 for a total population figure of 5.5 million, quite a bit less than the global population estimated at 8.1 billion. I’m guessing because this is “per adult” rather than per person. The children of the world are all on the low end of the wealth spectrum and probably would be a large share of the 3.6 billion.

Also questions can be asked about how they value wealth, do we consider debts, etc…in which case there’s a lot of people with zero wealth or less, as well as a lot of people who don’t have bank accounts and whose wealth is hard to measure is any ordinary sense. Point being, this particular comparison is kind of meaningless without more context. There’s probably ways you can do it to get an even larger number than 3.6 billion.

But a more useful and perhaps more surprising metric is that 8 people have as much wealth as 158 million median people. Which is still ridiculous, like those 8 people are worth a Russia’s entire population’s worth of people. And not just of poor people, but your average adult person.