#6 and #7 on the list are the Koch brothers. Under the categories "inherited" or "self-made" Bloomberg lists them as "self-made". Only 29 of the 100 are listed as having inherited their wealth. Ibn Saud's grandson, Alwaleed Al Saud is #16 and is also listed by Bloomberg as self-made. I guess even if you're the grandson of the guy your country is named after, you can still be listed as self-made by Bloomberg. Happy to see these self-made guys pulled themselves up by their bootstraps and became billionaires.