Alarms were blaring inside Wall Street’s corridors of power in the middle of last week, as executives realised they might be facing the biggest hedge-fund blowup since Long-Term Capital Management in the 1990s.Global investment banks, gathering in a hastily arranged call, needed a swift truce to deal with Archegos Capital Management – managed by former Tiger Asia hedge fund manager Bill Hwang – if they were to head off billions of dollars in losses for banks and a potential chain reaction…