This whole house of cards could come tumbling down so easily.

I just heard about a new service opening that will let you borrow against a Bitcoin balance at modest interest -- giving you cash.
Cash you can use to buy Bitcoin.
Then you can take that Bitcoin and put it into that service -- and borrow more USD against it! Rinse and repeat.

I'm sure the same thing was done in the past with Real Estate. Borrow money (HELOC) from your real estate portfolio, and use that money to buy house(s). Then, take out a HELOC on those houses -- possibly allowing you to buy another house! It all works until the price of houses starts to STAGNATE, nevermind starting to actually go down! Then everything has to unwind.

Then everything crashes like two towers suffering controlled demo.

Talk about building a house of cards up to the moon. Something's gotta give.