In recent days we’ve seen a series of stomach-churning downward lurches in global stock markets. Once again, sensible commentators are rightly urging investors to stay calm. Bailing out when markets have fallen sharply is almost invariably a bad idea. It might bring short-term emotional comfort, but you may well be paying a very high price for it in the long run. As the saying goes, ‘Act in haste, repent at leisure’.