One of the key elements in last year’s financial meltdown was that many of these bundles of loans became nearly worthless, causing the biggest sellers — such as Bear Stearns — to collapse.

“There are a lot of very smart people on Wall Street,” said William Cohan, author of “House of Cards,” a current best-seller that details the fall of Bear Stearns. “But as usual, these ideas get deconstructed as everyone wants to figure out how all that money is being made. Then, things get out of control.”

In this case, the push to get more people into homes began in the middle of the Clinton administration and continued during George Bush’s term. As lenders developed ever-more-attractive loans that made it easy for buyers to get into homes that they otherwise never would have qualified for, the minds on Wall Street cranked away on how to profit from the trend.

“A mortgage is a perfect vehicle. Everyone who touches it makes money,” Cohan told a large crowd Thursday at Oklahoma State University’s Tulsa Business Forum at the Crowne Plaza Hotel.

Bear Stearns became the biggest player in “securitizing” these loans, or lumping the mortgages together and selling them to investors around the globe. The packages initially carried top ratings, and were seen by buyers as a way to earn 6 percent to 7 percent at a time when returns elsewhere were scraping bottom.

However, when it started

“Cayne had a lot of chances to diversify away from the mortgage-based securities business, but he didn’t,” the author said.

Later, Cayne also had an opportunity to sell Bear Stearns, while there still was some value to the firm, “but he failed to do that as well,” Cohan said.

Why? The business had been very, very good to Cayne and other top officers. One year, Cayne and four other executives split $160 million in spoils, Cohan said. At the peak, Cayne’s stock alone was worth more than $1 billion.

That wasn’t bad for a man who started as a scrap-iron salesman and a professional bridge player. Cayne, in fact, got hired at Bear Stearns essentially so he could tutor another executive on bridge, according to Cohan.

By the time Cayne was running Bear Stears, he reportedly had a $27.4 million apartment and routinely took a $1,700 helicopter ride from the office to his golf club. And, he still was playing bridge — sometimes even directing the company via phone from a tournament.

But the house of cards he built on Wall Street was beginning to shake. Soon, Bear Stearns was financing its activities through an unusual method — getting $75 million daily in overnight loans, backed by the firm’s packages of home mortgages. When lenders got nervous about those securities and cut Bear Stearns off from the funding, bankruptcy was a certainty, Cohan said.

The author, who spent 17 years as a Wall Street banker, said he remains troubled that few of the leaders on Wall Street have accepted blame or been held accountable for their actions.

Cohan subtitled his book, “A Tale of Hubris and Wretched Excess on Wall Street.” As an example of that hubris, Cohan recounted a personal visit with Cayne following a long story the author did on him for Fortune magazine.

The article detailed Cayne’s rise and fall at Bear Stearns in painstaking detail. Cohan said he had done his investigative work and double-checked quotes with Cayne, but nevertheless was nervous as he could tell his subject was not pleased.

But instead of questioning any of the corporate strategy recounted or the complicated time line of events, Cayne denied he’d lost 30 pounds while hospitalized for a life-threatening condition six months before Bear Stearn’s emergency sale to JPMorgan Chase.

“People will think I was fat,” Cohan recalled Cayne telling him, doing an impression of the angry executive’s voice. Cohan had received the weight-loss number directly from Cayne’s doctor.

Cayne lost a billion dollars in stock value when Bear Stearns collapsed, Cohan said, but still has several hundred million dollars to live on.

In the future, Cohan said, Wall Street leaders should be required to put their own money at risk rather than just play with shareholders’ cash.

Otherwise, he said, the incentive will remain to take huge risks.

“The goal in the short term is to get as big a bonus as you can,” Cohan said. “On Wall Street, 50 percent to 60 percent of revenue is paid out in bonuses. No other business operates that way.”