Equity Stripping
You promised to pay back the loan on your home. But...you didn't. You put $100k down and borrowed $400k. There was equity in your home initially...that $100k. Then the total $500k value of the home either went down...or you just couldn't make the mortgage payments any more.
So a predatory opportunist vulture capitalist came around to show you...reality. And to clearly illustrate that bad things happen to good people all the time. So they equity-stripped you. That is, they took over your payments...and ownership of your home. But then agreed to lease the home back to you for some period of time, until your kids had gone off to college or The Poor House and you were left to live in your station wagon down by the river.
The entrepreneur will have stripped your equity from you, only to flip the house at a profit n years down the line.
Don't let this happen to you.