Le vertige des bourses mondiales

Le plongeon enregistré par les places financières mondiales le 9 août dernier, après l’annonce du gel de trois fonds par BNP Paribas, est un nouvel exemple de la récente instabilité à la baisse, ou de la tendance asymétrique négative, des marchés. En d’autres termes, les marchés se montrent plus sensibles à des plongeons soudains qu’à des flambées soudaines. De manière inhabituelle, les cours à la moyenne mobile à 100 jours clôturant le 3 ao_51ût ont été négativement asymétriques en Allemagne, Argentine, Australie, Brésil, Canada, Chine, États-Unis, France, Inde, Japon, Corée du Sud, Mexique et au Royaume-Uni.

Aux États-Unis, par exemple, l’indice élargi Standard’s and Poor 500 a enregistré en juillet six jours de baisse contre seulement trois jours de hausse de plus de 1%. En juin, l’indice a chuté sur 4 jours de plus de 1% et augmenté de plus de 1% sur 2 jours. En remontant dans le temps, on peut noter un très fort repli de 3,5% en un jour, le 27 février 2007, et aucun rebond sensible.

La baisse du 27 février a été provoquée par une chute de 8,8% en un jour de l’indice composite de la Bourse de Shanghai, lorsque le gouvernement chinois a annoncé que les plus-values seraient plus fortement taxées. Cette nouvelle, qui aurait dû n’affecter que la Chine, a entraîné un fléchissement de toutes les places financières mondiales. La Bovespa au Brésil a par exemple reculé de 6,6% le 27 février, et la BSE 30 en Inde, de 4% le jour suivant. Par la suite, les marchés ont lentement et progressivement récupéré.

To continue reading, please log in or enter your email address.

Registration is quick and easy and requires only your email address. If you already have an account with us, please log in. Or subscribe now for unlimited access.


Log in

  1. Patrick Kovarik/Getty Images

    The Summit of Climate Hopes

    Presidents, prime ministers, and policymakers gather in Paris today for the One Planet Summit. But with no senior US representative attending, is the 2015 Paris climate agreement still viable?

  2. Trump greets his supporters The Washington Post/Getty Images

    Populist Plutocracy and the Future of America

    • In the first year of his presidency, Donald Trump has consistently sold out the blue-collar, socially conservative whites who brought him to power, while pursuing policies to enrich his fellow plutocrats. 

    • Sooner or later, Trump's core supporters will wake up to this fact, so it is worth asking how far he might go to keep them on his side.
  3. Agents are bidding on at the auction of Leonardo da Vinci's 'Salvator Mundi' Eduardo Munoz Alvarez/Getty Images

    The Man Who Didn’t Save the World

    A Saudi prince has been revealed to be the buyer of Leonardo da Vinci's "Salvator Mundi," for which he spent $450.3 million. Had he given the money to the poor, as the subject of the painting instructed another rich man, he could have restored eyesight to nine million people, or enabled 13 million families to grow 50% more food.

  4.  An inside view of the 'AknRobotics' Anadolu Agency/Getty Images

    Two Myths About Automation

    While many people believe that technological progress and job destruction are accelerating dramatically, there is no evidence of either trend. In reality, total factor productivity, the best summary measure of the pace of technical change, has been stagnating since 2005 in the US and across the advanced-country world.

  5. A student shows a combo pictures of three dictators, Austrian born Hitler, Castro and Stalin with Viktor Orban Attila Kisbenedek/Getty Images

    The Hungarian Government’s Failed Campaign of Lies

    The Hungarian government has released the results of its "national consultation" on what it calls the "Soros Plan" to flood the country with Muslim migrants and refugees. But no such plan exists, only a taxpayer-funded propaganda campaign to help a corrupt administration deflect attention from its failure to fulfill Hungarians’ aspirations.

  6. Project Syndicate

    DEBATE: Should the Eurozone Impose Fiscal Union?

    French President Emmanuel Macron wants European leaders to appoint a eurozone finance minister as a way to ensure the single currency's long-term viability. But would it work, and, more fundamentally, is it necessary?

  7. The Year Ahead 2018

    The world’s leading thinkers and policymakers examine what’s come apart in the past year, and anticipate what will define the year ahead.

    Order now