The biggest commercial banking institution to fail in United States history by total asset size at the time of collapse is Washington Mutual, which succumbed to a catastrophic liquidity crisis and depositor run in September 2008 with approximately 307 billion dollars in assets. The institution's aggressive expansion into toxic subprime mortgages and Alt-A loans during the housing boom rendered its balance sheet critically vulnerable when the property market imploded. Federal regulators closed the institution and sold its massive branch network to JPMorgan Chase in a historic transaction that surpassed all previous banking collapses in scale, cost, and immediate economic impact on the domestic financial system.