Strict documentation requirements for new borrowers resulted in a liquidity crisis for real estate due to a lack of qualified borrowers.

Initial loan-to-value ratios steadily decreased for new subprime borrowers in the years leading up to the crisis.

Most mortgage brokers were compensated based on the performance of subprime mortgages they originated, and were forced to pay back large commissions as loans began to fail.

Interest rates rose sharply on many subprime mortgages after a short initial low-rate period, forcing some borrowers to default.