China Reveals The Perils Of Leverage

 | Jul 08, 2015 01:03PM ET

I have, on more than one occasion, discussed the surging levels of margin debt (see here and here) in the U.S. markets. These discussions were met by opposing points of view suggesting that margin debt doesn't matter.

Jesse Felder noted the same recently in his post "Why Record-High Margin Debt Should Make You More Cautious." To wit:

It's recently become popular to dismiss the record level of margin debt in the market as meaningless. Notable bloggers like Josh Brown, Barry Ritholtz and Chris Kimble have all written some sort of 'it just doesn't matter' commentary recently. Barry went so far as to call it, 'statistically bogus.' To me, this sounds like just another version of, 'it's different this time.

The problem is that margin debt DOES matter, and it potentially matters a lot. As I stated previously:

It is worth noting that when net credit balances have plunged very negative levels it has been coincident with major mean reverting events in the market.

While 'this time could certainly be different,' the reality is that leverage of this magnitude is 'gasoline waiting on a match.' When an event eventually occurs, that creates a rush to sell in the markets, the decline in prices will reach a point that triggers an initial round of margin calls. Since margin debt is a function of the value of the underlying "collateral," the forced sale of assets will reduce the value of the collateral further triggering further margin calls. Those margin calls will trigger more selling forcing more margin calls, so forth and so on.

Notice in the chart that margin debt reductions begins innocently enough before accelerating sharply to the downside.