Paris (AFP)

Dark day for the Paris Stock Exchange and several other places managed by Euronext: after suffering a blackout of about three hours in the morning, the European stock market operator saw the exchanges extend well beyond the usual closing time and finally canceled all those that occurred after 5.30 p.m.

In addition to Paris, the places of Brussels, Amsterdam, Lisbon and Dublin, also managed by Euronext, were affected.

"The markets did not close as expected (...) for reasons which are being investigated," said the pan-European operator in a statement sent Monday evening to AFP.

Sudden movements occurred just after the usual closing time of 5.30 p.m.

Some stocks then returned close to their level of the day, but others did not make up for the loss, such as Saint-Gobain, which collapsed in these unusual late exchanges of 7.98% to 33.80 euros .

"Because of these problems, Euronext has decided to cancel all trades that occurred after 5.30 p.m. on all asset classes, except commodities," the statement continued.

The flagship index of the Parisian market, the CAC 40, therefore ended at 4,942.62 points, up 0.14%, told AFP Euronext.

- Three hour outage -

Earlier today, quotes had already been suspended for nearly three hours in these same places.

"The cause [of the failure] has been identified and resolved," assured the pan-European stock market operator in a statement shortly before the reopening of trading at 12:45, indicating that it was a "technical problem".

"A blackout can happen once or twice a year, but it has been unusually long," said Lara Nguyen, private manager at Fastea Capital, who said she "never experienced this situation." in more than 20 years of career ".

The operator did not give any other information on Monday evening on the cause of this first failure, just evoking a computer problem.

This notably affected fixed rate transactions, liquid transactions linked to the equity market and those linked to index funds (ETF), most of which could have been available again between 12:30 p.m. and 1:00 p.m., Euronext said.

In contrast, the market for warrants, financial products that can be converted into shares, did not recover all day, Bloomberg reported.

The last major outage that affected the stock market operator dates back two years, when on October 29, 2018, a failure to calculate the CAC 40 at the start of the session had caused a suspension of listing and disruptions throughout the morning.

- Serial problems on world stock exchanges -

The blackout suffered by Euronext on Monday comes shortly after a series of technical problems that affected several stock exchanges around the world.

The most recent dates back to October 1 and a blockage throughout the session on the Tokyo Stock Exchange, one of the most serious incidents in the history of the Japanese market.

It was preceded by an interruption of trading in July on the Frankfurt Stock Exchange, due to a "malfunction" that affected the trading system of this financial center, called Xetra.

The "bug" suffered by Euronext on Monday did not seem to have affected investors' mood too much.

Customers were "quite patient", responded to AFP Christopher Dembik, head of economic research at Saxo Bank.

The expert observed "the advantage of having a rather quiet Monday", with traditionally low order volumes on the first day of the week.

The technical woes affecting Euronext occur only ten days after the latter's formalization of the takeover of the Milan Stock Exchange, held for twelve years by the London Stock Exchange, which manages the London Stock Exchange.

The acquisition was made with the Italian Caisse des Dépôts and the Italian bank Intesa Sanpaolo.

© 2020 AFP