I just had an argument with someone on this. My position was that rising fuel prices and the resulting shock across the economy was the trigger that collapsed the house of cards caused by the CRA and imprudent lending standards then occurring throughout the lending markets.
It was the liar-loans/no-documentation/fraudulent-loans all enabled by Fannie Mae & Freddie Mac buying them up and guaranteeing these worthless loans at taxpayer expense. No other significant factors were really involved. Except for the government complicity part, “The Big Short” gives an excellent account of what happened and why.
According to the movie, the main thing that triggered the collapse of the housing bubble was the first wave of ARM loans which reset (with payments going up) in 2007. That’s what the people who were shorting the mortgage backed securities were counting on, along with the predictable wave of mortgage defaults and foreclosures that followed.
Multiple factors contributed. Fuel prices were one of many.
I’d point out that one reason for the fuel prices and related dotcom boom and bust is that Clinton created artificial prosperity by releasing the federal oil reserves at rock bottom prices which fueled much of the dotcom speculation. That was like running up your credit cards for several years, then being forced to pay them off. The party was good while you were spending like crazy (Democrat years) but a lot less fun when you ran out of what you thought was free money and had to get a job and pay the bills (Republican years).