Anyone can found a company with a $1 market cap and have full ownership from their one dollar investment. But it's meaningless unless they turn that into an actually valuable company with a market cap in the billions. Thiel just got exceptionally lucky, in addition to a bunch of hard and smart work.

I think this is a concept a lot of us struggle with when imagining the extreme wealth of the most elite tech entrepreneurs. Bezos, Gate, Zuck, and the rest all started with worthless companies and had substantial ownership as founders. Their wealth came from turning those large stakes in worthless companies into slightly smaller stakes into companies worth hundreds of billions.

I don't know where to find the documents on Paypal's valuation and early ownership transactions to be able to dig further into this. One would imagine Propublica would have done so if it were feasible, and reported on it.

26 U.S. Code § 4975(2):

(H)an officer, director (or an individual having powers or responsibilities similar to those of officers or directors), a 10 percent or more shareholder, or a highly compensated employee (earning 10 percent or more of the yearly wages of an employer) of a person described in subparagraph (C), (D), (E), or (G)

The propublica article says Thiel put shares of his own company in his IRA. If true, that's not something you can do anyone.

Making those shares worth billions of dollars is left as an exercise for the reader.

It cannot be your primary residence.

You have to be entirely hands-off with it. You are not allowed to manage the property, do repairs, etc.

You are still not allowed to decree that the value of a house that you own is $10 and sell it in to your Roth in order to shelter it from taxes and get around contribution limits.