The engines at Euronext have a reputation comparable with French cars. Unreliable and panne at the worst thinkable moments. In the past years the triple witching hours have been most likely to see trading halts. Recently the market shut down on December 15th and November 27th – but this year we did not experience any trouble. A whole quarter without glitches.

Until last weekend’s system upgrade

Last weekend, the system engineers at Euronext decided it was a good moment for upgrade a router. Monday morning, the derivative markets at Euronext suddenly started to experience trouble shortly after the opening. A short while markets remained operating at half speed with half of the participants in the dark. Ten minutes later the exchange was forced to close the doors.

All derivative trading halted for most part of the morning. Market makers complained about unexpected trade executions while they assumed systems were down and orders had been pulled. Trading has been restarted, but some problems at Euronext persist.

If it ain’t broke, don’t fix it

Until further notice most performance reports from Euronext – usually supplied on a daily basis – have been suspended. Here’s the official explanation in pdf. Apparently Euronext is trying to downplay the glitch – the problems started just after opening instead of 10:10.

Morale of the story is clear. If it ain’t broke, don’t fix it.

• Euronext, glitch