Last Friday, global equities suffered their worst day since several years of complacency and low volatility ended with the dive of February 27 last year. While that crash came from nowhere, there were good reasons for this latest one. But they may not have been the reasons that people thought.

US non-farm payrolls, a noisy indicator prone to big revisions, sparked the sell-off. The rise in the unemployment rate from 5 to 5.5 per cent was scary, while total payrolls fell for the fifth month in a row.