(Bloomberg) -- The seeds of First Republic Bank’s downfall were sown in the jumbo mortgages of Silicon Valley, where a unique strategy to loan wealthy individuals extraordinary sums of money blew up in spectacular fashion.Most Read from BloombergJPMorgan Ends First Republic’s Turmoil After FDIC SeizureBuffett Will Beat the Market as Recession Looms, Investors SayPeak Oil Spells Trouble for ConsumersJerome Powell Could Face More Opposition as Fed Choices Get TougherFirst Republic Talks Extend Int