After every great crisis, a simple question arises: Who knew?

Lewis Ranieri, who pioneered mortgage backed securities when he worked at Salomon Brothers in the late 1970s and more recently warned against their misuse, is the latest victim of the nation’s housing crisis.

A bad year for homeowners meant a good year for John A. Paulson. Paulson, the founder and president of the hedge fund Paulson & Company, made $3.7 billion last year, according to an annual listing of the 50 most highly paid hedge fund managers.

Troubled Washington Mutual, the nation’s largest savings and loan, has seen its stock price nearly double from its lows over the past month. Takeover speculation has certainly helped, as have the Federal Reserve’s interest rate cuts.

But don’t discount the importance of the message chairman and CEO Kerry Killinger sent when he decided not to take a 2007 bonus that he had earned. Executives at other companies caught in the real estate mess — Countywide Financial and D.R. Horton, for example — have not set the same example of accountability.

Countrywide Financial is being swallowed by Bank of America, but don’t cry for Angelo Mozilo, Countrywide’s embattled CEO.

The butcher’s son from the Bronx who founded Countrywide in 1969 could walk away from the deal with $70 million or so, according to The New York Times.

Difficult times for a company mean difficult times for its board of directors.

And these certainly are difficult times for Washington Mutual, the nation’s largest savings and loan.

Because of losses related to subprime mortgage lending, the Seattle-based firm has closed operations, cut jobs, slashed its dividend, and watched the price of its stock plummet to its lowest level in more than 11 years, closing Friday at $13.07.

For much of the past year, IndyMac has been zigging while the rest of the troubled mortgage industry has been zagging.

The big California-based lender built a retail force of almost 1,500 people, largely by hiring workers from failed and troubled mortgage competitors.

Friday, however, the tables turned. IndyMac said it plans to cut 1,000 jobs, 10 percent of its total workforce, trim its stock dividend and possibly post a loss in the third quarter as it converts almost all of its business away from riskier borrowers to conforming loans that can be dealt to Fannie Mae and Freddie Mac.

It’s one thing when stock market analysts knock your company’s prospects. Even worse when your auditor does the same.

Subprime lender NovaStar Financial cancelled plans to raise $101 million Tuesday saying its auditor, Deloitte & Touche LLP , wanted to include a statement in the company’s financial disclosures about the “uncertainty of NovaStar’s ability to continue as a going concern.”

Accredited Home Lenders, the troubled mortgage company with two former S&L regulators on its board, lost a key director this week.

A. Jay Meyerson, the former CEO of Aames Investment Corp., resigned effective immediately. Meyerson joined Accredited board’s last October, when Accredited acquired Aames.

Thursday, a day after Meyerson resigned, Lone Star Fund informed Accredited that it was lowering the price of its takeover offer to $8.50 a share. In June, Lone Star offered $15.10 a share.

While other funds struggle through the mortgage crisis, a hedge fund founded by former Harvard Management Co. CEO Jack R. Meyer is flourishing.

Meyer and former Harvard colleagues run Convexity Capital Management, which makes trading bets that benefit from volatility. The fund, started last year, had disappointing early results. But recent market swings have brought a turnaround.