3 ideas
No-money-down deals only work when the seller needs to sell more than they need cash, because of divorce, job transfer, a vacant property or a looming foreclosure. That urgency lets the buyer swap a cash down payment for seller-carried notes, deferred payments or other paper. The seller ends up bearing the credit risk the buyer avoided.
The buyer covers the gap between price and first mortgage with layered sources: the seller carries back a second note, other liens are assumed, the realtor's commission is deferred, or equity is borrowed from another property. The result is 100% or more financing.
The book argues that controlling a property with almost no cash invested makes returns on cash effectively unlimited as prices rise. The same structure means even a small drop in price or rent leaves the buyer with negative equity and negative cash flow, with no cushion to absorb it.