GM debt has been through a lot of late. In May 2009, car czar Steve Rattner made a bold and unexpected decision to nationalize the company rather than leave it with debt outstanding. That decision was followed by a CDS auction which valued GM’s defaulted debt at just 12.5 cents on the dollar — a valuation unthinkably low just a couple of years earlier. Clearly, when it comes to automaker debt, there’s a lot of uncertainty and volatility — and where there’s debt with uncertainty and volatility, there’s sure to be CDS trading.

The WSJ, however, has decided to take a golly-gee approach to the whole thing, larded with a good sprinkling of demonization. I’m surprised to see veteran bond-market reporter Matt Wirz—a genuine expert when it comes to such things—with a byline on this:

Fresh from Wall Street’s alchemy labs: Credit derivatives tied to General Motors Co. debt. The rub is, no such debt exists…

Investors who bought “naked CDS” to bet on the likelihood of default, rather than to hedge risk from other investments, are credited with worsening the liquidity crisis that gripped financial powerhouses, prompting calls for tighter regulation of the industry.

First of all, there’s no alchemy here. You might not like credit default swaps in general, but they’ve been around a long time, and there’s nothing new or innovative about CDS on GM. Sure, the amount of GM debt outstanding is low, but it’s a bit weird to say that “no such debt exists,” given that there’s still $4.6 billion in bank debt outstanding.

The assertion about the nonexistence of GM debt is backed up with a single extremely vague sentence:

Banks, some of which have made loans to the car maker, have been buying the CDS even though it is unclear whether the contracts would cover their debts, according to people familiar with the matter.

Nowhere is it explained what this is supposed to mean; I’m guessing that there’s a question as to whether a default on GM’s bank loans would trigger the CDS. And then there’s also the question of what would be auctioned and delivered in any CDS auction:

When a company files for bankruptcy or fails to meet its interest payments, the market stages an auction to determine the value of the defaulted debt, and how to compensate the CDS holders.

The value assigned to the CDS relies on investors being able to buy and sell bonds in the open market, so it is problematic for the newly revived GM not to have any bonds outstanding.

This isn’t really true. CDS auction prices are emphatically not a function of the open-market secondary-market price for individual bonds: that’s why there’s an auction in the first place. Would bank loans not be eligible to be tendered as cheapest-to-deliver debt securities? The article doesn’t say. But whenever any company has $4.6 billion in bank loans outstanding, there’s a secondary-market price for those loans, so in principle it should be possible to find them and deliver them. If the number of loans outstanding is small, then that just creates a familiar problem in the CDS market, when the amount of CDS written is larger than the amount of debt outstanding. The CDS market has dealt with that problem many times, and it’s not really an issue any more.

In any event, it has long been common practice for banks to hedge their loan exposure in the CDS market — that’s one of the generally-accepted “legitimate”, or non-naked, forms of CDS trading. There’s a reason why they’re called credit default swaps rather than bond default swaps.

But more to the point, the WSJ seems to be willfully naive about what’s going on here. Why would you sell credit protection on GM debt? Because it currently has very little debt outstanding, because you don’t think it’s going to reach a remotely dangerous level of debt in the next five years, and because you get to cash a steady flow of CDS premiums in the interim. Essentially, exactly the same reasons that you would buy GM bonds, if any existed—only selling protection is much cheaper, so you get a higher internal rate of return.

Felix Salmon is an Audit contributor. He's also the finance blogger for Reuters; this post can also be found at Reuters.com.