Billionaire investor Edward Lampert bought KB Home and Centex Corp. shares in the first quarter even as most homebuilders fell to a five-year low, Bloomberg News reports.

Lampert's ESL Investments Inc. hedge fund purchased 747,500 shares of Centex, the fourth-largest builder, according to a May 15 filing with the U.S. Securities and Exchange Commission. The shares are valued at $10.4 million at yesterday's closing price. The fund also acquired 605,000 shares of KB Home as of March 31, the fifth-largest, valued at $10.8 million.

In January, a Standard & Poor's measure of U.S. homebuilders tumbled to the lowest since December 2002 as prices fell and banks cut financing. The index then rallied 57 percent, hitting a high for this year on April 3 on expectations Federal Reserve interest rate cuts would boost demand. Since then, the index has fallen 33 percent.

Stricter lending standards, falling home prices and rising foreclosures have led the Standard & Poor's Supercomposite Homebuilding Index to fall 53 percent in the 12 months through yesterday.

Lampert, the chairman of Sears Holding Corp., is also investing in mortgage-related companies.

The SEC filings were made by RBS Partners LP, the Lampert affiliate that reports the fund's positions.