2008 was a lot of 'AAA' grade securities not being able to find a greater fool to keep the profit train running. A lot of financial instruments were basically r

2008 was a lot of 'AAA' grade securities not being able to find a greater fool to keep the profit train running. A lot of financial instruments were basically repacking and reselling loans with a bit of interest on top. Once there were no more new buyers it was a cascade of margin calls. Subprime was a very small cause of the GFC but it was the tipping point that brought the house down.