A nuclear winter?

WHEN Warren Buffett said that derivatives were “financial weapons of mass destruction”, this was just the kind of crisis the investment seer had in mind. Part of the reason investors are so nervous about the health of financial companies is that they do not know how exposed they are to the derivatives market. It is doubly troubling that the collapse of Lehman Brothers and the near-collapse of American International Group (AIG) came before such useful reforms as a central clearing house for derivatives were in place.

A bankruptcy the size of Lehman's has three potential impacts on the $62 trillion credit-default swaps (CDS) market, where investors buy insurance against corporate default. All of them would have been multiplied many times had AIG failed too. The insurer has $441 billion in exposure to credit derivatives. A lot of this was provided to banks, which would have taken a hit to their capital had AIG failed. Small wonder the Federal Reserve had to intervene.

The first impact concerns contracts on the debt of Lehman itself. As a “credit event”, the bankruptcy will trigger settlement of contracts, under rules drawn up by the International Swaps and Derivatives Association (ISDA). Those who sold insurance against Lehman going bust will lose a lot. But Lehman had looked risky for some time, so investors should have had the chance to limit their exposure.

The second effect relates to deals where Lehman was a counterparty, ie, a buyer or seller of a swaps contract. For example, an investor or bank may have bought a swap as insurance against an AIG default, with Lehman on the other side of the deal. That protection could conceivably be worthless if Lehman fails to pay up. Until the Friday before its bankruptcy, Lehman would have posted collateral, which the counterparty can claim. After that day, the buyer will have been exposed to price movements before it could unwind the contract.

The third effect will be on the collateralised-debt obligation (CDO) market, which caused so many problems last year. So-called synthetic CDOs comprise a bunch of credit-default swaps; a Lehman default may cause big losses for holders of the riskier tranches.

Insiders say the biggest exposure may be in the interest-rate swaps market, which is many times larger than those for credit derivatives. In a typical interest-rate swap, one party agrees to exchange a fixed-rate obligation with another that has a floating, or variable, rate exposure. Depending on whether floating rates rise or fall, one will end up owing money to the other. Again, those banks that dealt with Lehman should have been fine until Friday, when the bank was still posting collateral. But not afterwards.

Although there are ISDA rules to cover such events, the sheer size of Lehman in the market (its gross derivatives positions will be hundreds of billions of dollars) makes this default a severe test. There will inevitably be legal disputes as well. The good news is that the swaps markets did not utterly seize up after it went bust on September 15th. But the reaction may be a delayed one. Mr Buffett's WMD could leave behind a cloud of toxicity.