SANMINA-SCI, the supplier of electronics services, is loaded with debt and in each of the last eightyears has lost money. Its shares have risen more than 600 percent since the stock market rally began on March 9.

Wal-Mart Stores, the discount retailer, has lots of cash on its balance sheet, has very little debt and has consistently turned a profit. Since March 9, its shares have gained just 14 percent.

The disparate treatment meted out to these two companies by the stock market highlights an unusual and, in some ways, worrisome phenomenon: to an extent not seen in decades, shares of companies with weak balance sheets have been soaring, generally outperforming firms with stronger fundamentals.

In part, this is a consequence of the terrible pummeling given to riskier assets of all kinds during the worst months of the financial crisis. Shares of companies that were deemed to be weakest were hit the hardest. It’s only natural that they would bounce back the most at the first hint that financial disaster had been averted.