CNN —Silicon Valley Bank’s astonishing fall Friday began when its customers rushed to draw down their accounts all at once — a destabilizing event known as a bank run. The bank provided financing for almost half of US venture-backed technology and health care companies. It was the largest failure of a US bank since Washington Mutual in 2008, during the Great Recession. Although the bank’s fall unfolded over a rapid 48 hours, the story begins years ago with moves made by the Fed and investment decisions by the bank. Here’s what led to the demise of a Top 20 US commercial bank:

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