In any case, by 2006, the wheels had started to come off the NovaStar cart. The company’s net income that year was less than half what it earned in 2005. The company faced a number of lawsuits, including a class action filed in Washington State in December 2005 alleging that NovaStar failed to disclose to borrowers the fees earned by brokers. Plaintiffs contended that NovaStar had violated consumer protection laws. In 2007, NovaStar agreed to pay $5.1 million to resolve the claims of about 1,600 Washington borrowers.

Its stock was falling, too. By late 2006, NovaStar was trading at around $30; but in the first few months of 2007, as the money for subprime lenders began drying up and these companies started closing their doors, it plummeted to $5. The company halted mortgage lending and stopped paying its dividend.

In March 2007, Mr. Anderson dismissed as insignificant the HUD report and the lawsuits the company had attracted. “Clearly we’re going through a tough time right now,” he told a reporter. “But we think the loans we are originating today will perform very well. We were surprised by the speed and severity of the downturn, but I think NovaStar will be a survivor.”

He was wrong. NovaStar’s shares collapsed, wiping out roughly $1 billion in market value from the peak of the stock price. Despite the implosion, between 2003 and 2008, Mr. Anderson and Mr. Hartman each made about $8 million in salary, bonuses and stock grants.

Neither man was ever sued by the S.E.C. or any other regulator. As is its custom, the S.E.C. declined to comment on the NovaStar inquiry or the agency’s discussions with short-sellers. But documents supplied by the S.E.C. under the Freedom of Information Act show the extensive communications between Mr. Cohodes and the agency. Ms. Miller, still at the S.E.C., declined to comment.

“It would be interesting to see who exactly dropped the ball, and why,” Mr. Cohodes said. “It would be interesting why nothing was ever brought. The S.E.C. should have sent a plane for us to come to D.C. and say: ‘How do we make sure this doesn’t happen again?’ ”

NOVASTAR no longer underwrites mortgages. Its shares were delisted by the New York Stock Exchange and now trade for about 41 cents a share. The company, a shadow of its former self, runs a property appraiser and a financial services unit that provides banking services “to meet the needs of low- and moderate-income-level individuals.”