Investors suffering from lack of sleep about the global stock markets continuing their volatile streak should have sought solace in caffeine.

Further declines in the stock markets this week saw the FTSE 100 nosedive under 5,000 points to reach as low as 4929.55 and register its biggest one day drop since March 2, 2009. Meanwhile, the fear register, volatility index, the Vix, jumped to its worst reading in eight sessions and closed up 35% at 42.67 on Thursday.