New Century’s stock price, which seemed to mirror the trajectory of the subprime business, peaked at nearly $66 a share in December of 2004 and traded in the $40s most of last year; on Friday, it was trading at $11 a share after the market closed. In a series of sales from August to November, two of the company’s founders sold shares for an average price of about $40 a share, for a total profit of $21.4 million.

It is not known whether the stock sales by the founders are among the sales being examined by federal investigators. Some of them had been part of scheduled stock sales that are often used by executives to diversify their portfolios. But some of the sales occurred on the same day that the executives entered the plans. A New Century spokeswoman, Laura Oberhelman, said that executives declined further comment.

The founders’ stock also rose in the social circles of southern California, the epicenter of the boom in subprime. Five of the 10 biggest providers of subprime mortgages last year had their headquarters in the region.

Robert K. Cole, 60, a co-founder who retired as chairman and chief executive last year, lives in a 6,100-square-foot oceanfront home in Laguna Beach that is valued at tens of millions of dollars and was once owned by the chief executive of Pimco Advisors, the giant bond trading and management firm. Edward F. Gotschall, 52, another co-founder who is vice chairman of the board, donated $3 million for an expanded trauma center at Mission Hospital that will be named for him and his wife Susan.

The executives from New Century are by no means alone in cashing in on the bonanza, and they do not appear to have scored the biggest profits. That title may be claimed by Angelo R. Mozilo, the chief executive of Countrywide Financial, the nation’s largest stand-alone mortgage company and one of the largest subprime lenders last year. He reaped more than $270 million in profits from sales of stock and the exercise of stock options from 2004 to the start of this year, according to the Thompson analysis.

Of course, most of the 500,000 people who work in the mortgage industry did not cash in so grandly. The wealth was concentrated among executives, loan officers and brokers, because the greatest rewards were meted out in the form of commissions, bonuses and stock awards.

“In the hot times, it was not unusual to see a broker make a million bucks,” said Guy Cecala, publisher of Inside Mortgage Finance, a trade publication. “You can carry that up further to people who ran the companies. The whole business revolves around personal compensation.”