Despite the expectation of grim reports that are to be released later this week, shares in local homebuilders surged Monday.

Shares in Los Angeles-based KB Home and Calabasas-based Ryland Group Inc. each gained more than 5 percent Monday, ahead of the report on sales of existing homes in September, set to be released Wednesday by the National Association of Realtors. Industry experts have estimated that the report will show a 5 percent to 6 percent drop in sales from last year.

More bad news is expected Thursday, when data on sales of new homes for the month of September will be released. Industry experts are also predicting declines of 8 percent or more for this report.

However, shares in KB added 6.3 percent Monday, $1.60, to $27.31, while shares in Ryland jumped 6.9 percent, or $1.65, to $25.56.