At the beginning of 2008, Chesapeake had a market value of $23 billion. Four months ago this company had a market value of $43 billion. A few weeks ago, that market value had fallen to $7 billion, and today it stands at $12.7 billion. I'm getting a bout of vertigo just typing these numbers.

I know what you're thinking. "What's the big deal? All of the banks are getting killed these days." That's fine, but this isn't a bank. This is the largest independent producer of natural gas in the United States. They have a strong exploration and production track record and hold some large and interesting acreage positions.
$43 billion to $7 billion in a few months. That's a decline of over 80%. That works out to over a 300% annualized loss (it's the new math). Immediately, one's thoughts wander to Enron. These guys must have been cooking the books. They must have overstated the amount of natural gas reserves they own, right? Wrong. So what's going on here?
For starters, we have to put that 80% decline in context. The market overall hasn't been exactly kind to anyone since the end of July. From the time of CHK's peak to its bottom earlier last month, the S&P 500 fell about 30%. It didn't help that natural gas prices fell 53% over this same time period in sympathy with oil prices (down 43%) as the global economy continued to sputter. XOP, the SPDR S&P Oil & Gas Exploration & Production ETF, was down 62% over this period. Still, CHK has outdone itself by falling further than any of these.
There is an added wrinkle to the CHK story. Chesapeake's CEO, Aubrey McClendon, owned about 32 million shares of CHK on October 8th. A couple of days later, most of those shares were gone. Loss of confidence in the company? Not exactly. McClendon was hit with a margin call. Amazingly, this billionaire thought it wise to keep adding to his already sizable CHK stake by buying on margin as the stock started falling this summer. You have to admire his belief in the company while questioning his money management strategy.
It boggles the mind that a billionaire would risk his fortune by buying stock on margin and not diversifying his holdings, but that's what McClendon did. This is a massive failure in Financial Planning 101. Amazingly, he wasn't alone.