Overturned Glass-Steagall.
Yes, but G-S wasn't the origin of the crash. The Community Reinvestment Act passed under the Carter admin precipitated the whole thing. Banks and lending institutions were forced to create sub-prime loans.
All based on a lie...that lending institutions were deliberately discriminating against i.e. redlining minorities, chiefly blacks. No enforcement of the CRA under Slick Willy, no creation of sub-prime loans, no subsequent credit default swaps, and no crash in 2008.
If you think that’s the main cause, you’re an economic ignoramus..