(Corrects name of conference to Delivering Alpha in first paragraph) WASHINGTON (Reuters) - The collapse of the British pound and subsequent sell off .
Customarily, the Fed and other central banks do as much as they can to keep markets calm and keep the economy on track. But now they're seen as the ones stoking volatility.
The scale and speed of the sell-off in British assets has jolted world markets, raising concern about contagion as chaos in a major developed economy adds to unease already generated by sharp.