Promoting efficient, orderly and fair markets is the first of the Financial Services Authority's three strategic aims. Yet for half an hour yesterday, between 8.30am and 9am, the market in HBOS shares was inefficient, disorderly and palpably unfair. At one point the stock was down 17 per cent, rocked by frenzied, high-volume trading on negative rumours that the bank denounced as malicious lies.

On the face of it, this looks like blatant market abuse. The FSA rushed out an unusual statement confirming it was investigating trading in "UK financial shares" and warning it would "not tolerate" short-sellers spreading false rumours and dealing on the back of them. The Bank of England had to quash speculation about emergency meetings. HBOS - and many analysts - pointed out the bank was solid.