It may go down in the history books about Silicon Valley: the time that its most prominent bank, a bank founded nearly 40 years earlier, inflicted such grievous injury on itself that it had to be rescued by another bank or else risk going down in flames in a single day. If you’re just catching up, here’s what happened: Silicon Valley Bank lost $1.8 billion in the sale of U.S. treasuries and mortgage-backed securities that it had invested in, owing to rising interest rates. The plan was to sell $1.25 billion of its common stock to investors, $500 million in convertible preferred shares, and $500 million of its common stock in a separate transaction to the private equity firm General Atlantic.