Shares plunged in the US and Europe this week over shadow banking fears - Spencer Platt/Getty Images The frenzied stock market sell-off that gripped the US and UK this week was fuelled by fear as much as fact. Investors saw what could easily be the tip of an iceberg, and nobody knows quite what lies beneath. Two car parts suppliers with multibillion-dollar debts in the private credit market have gone bust amid allegations of fraud, and two regional US banks have uncovered a clutch of irredeemably bad loan ...