Short selling is the Marmite of financial markets. Like the British breakfast spread, you either love it or hate it. Continental European types typically hate Marmite, and shorting – borrowing and selling stocks in the hope they fall – appeals to them even less. On Thursday France, Italy and Spain extended two-week-old bans on shorting financial shares, and Belgium’s remains.

The effects have been much as might be expected. Excluding people with negative views on European banks from the market led to an immediate pop in share prices.

But shareholders realised the dangers, and prices fell back. In Thursday’s trading protected banks were briefly worth more than before the ban, but fell back. Across the four countries, bank market values have dropped €1.2bn ($1.7bn).