Help me Understand Equity? It seems Arbitrary

[Charles Montgomery]

I dont really understand equity, especially on the buy/hold strategies. It seems like equity is subjective and speculative.

For example, reading some of the BRRR threads. People talk about Cash out refinancing for 70-80$ LTV, leaving the investor with 30-30% equity. But, does equity really equal wealth?

If I buy a house and rehab it all with cash, say $150K total, and that house is worth $150K. I have 100% equity. But do I have wealth? Great, I get cash flow from renters, but if the home loses value,, I still have 100% equity, its just that I have 100% of a lesser value.

I feel like I am overthinking. Just trying to figure out if buying some turnkey rentals is a good place to have my money tied up, versus tying the money up for shorter periods of time by flipping.