[artisinal]

Not American here. I know a couple of people who took out a second mortgage to buy a small appartement to rent out when mortgages rates were at 1%. They probably have €300k in equity in both the primary and secondary home. And around €600 in income from the rental. I do not consider that wealthy.

[torginus]

I would describe that as having invested in an appreciating asset (like stocks), and their main income comes from the gains of the property prices as they go up in value. Moreover, they leveraged themselves via loans to acquire income even faster.

These gains might be realized at any point if they're willing to pay taxes for them.

Having lots of money but choosing not to spend it doesn't make you any less wealthy.