Once the phantom collateral vanishes, there's no foundation to support additional debt and leverage.
When a speculator bought a new particle-board-and-paint McMansion in the middle of nowhere in 2007 with nothing down and a $500,000 mortgage, the lender and the buyer both considered the house as $500,000 of collateral. The lender counted the house as a $500,000 asset, and the speculator considered it his lottery ticket in the housing bubble sweepstakes: when (not if) the house leaped to $600,000, the speculator could sell, pay the commission and closing costs and skim the balance as low-risk profit.
But was the house really worth $500,000? That's the trouble with assets bubbles inflated by central-bank/central-state intervention: when inefficient companies and inflated assets are never allowed to fall/fail, it's impossible to tell the difference between real collateral and phantom collateral.
The implosion of the housing bubble led to an initial spike of price discovery. The speculator jingle-mailed the ownership of the poorly constructed McMansion to the lender, who ended up selling the home to another speculator who reckoned a 50% discount made the house cheap for $250,000.
But what was the enterprise value of the property, that is, how much revenue, cash flow and net income could the property generate in the open market as a rental? Comparables are worthless in terms of assessing collateral, because assets are mostly phantom collateral at bubble tops.
Let's assume the enterprise value based on market rents was $150,000. The speculator who bought the house for $250,000 sold for a loss, and at the bottom of the cycle the house finally sold for its true value of $150,000.
Leveraged 20-to-1, the lender's loss of $250,000 in collateral/capital unhinged $5 million of the lender's portfolio as the capital supporting those loans vanished.
The first speculator who put nothing down suffered a loss of creditworthiness, and the second speculator lost $100,000 plus commissions when he dumped the property for a loss.
