Investors got ECB odds wrong but Draghi could pay hefty price

Mario Draghi's authority has been dented after he dashed investors' hopes. It would seem a central banker is only as trustworthy as his last statement

It's hard to know who is most to blame: Mario Draghi, for leading investors up the garden path; or investors, for believing that the European Central Bank president's talk of doing "what we must" equated to a firm promise of a bigger dose of quantitative easing.

Either way, the marriage of a teasing central banker and a gullible set of investors produced an ugly stock market on Thursday. The French and German markets fell 3.6% and even the FTSE 100 shed 146 points, or 2.3%.