When asked to explain the events of last week, most City analysts were uncharacteristically lost for words.

“It’s turned into a casino,” one managed to say. “Investors’ heads are spinning like the girl in the Exorcist.”

Short-selling was one cause of confusion – or rather the uncertainty over the extent to which it was going on.

Many short-sellers ended last week with burned fingers, as a clampdown by the Financial Services Authority led to fears that more widespread restrictions would come into force.

As short-sellers closed their positions by buying back on-loan stock on Friday, share prices went up. Barratt rose 14% to 148p and Taylor Wimpey rose 17% to 55p. It was a “one day wonder” according to Robin Hardy, an analyst at KBC Peel Hunt, and shares quickly lost ground again at the start of this week. “It’s all got a bit nastier post-Lehman,” he said.

The fact Barclays waited for Lehman to go into administration, rather than ride to the rescue sooner, also raised eyebrows. Hardy said: “They smashed the pot and picked up the pieces. The banks could now conclude they can get their money back through force.” Housebuilders beware.