Le déclencheur de cette « journée d'hystérie collective », selon les témoignages de l'époque ? A leading-edge research firm focused on digital transformation. It took a confluence of events to tank the market that fateful October. This cash settlement mismatch forced traders and investors to wait two days for stock trade proceeds to arrive in their accounts even though payments for options and futures trades were required after one day. En quelques heures, le Dow Jones perd plus de 500 points, soit une chute de 22,6 % qui pulvérise le record du 29 octobre 1929 (-12,6 %), point de départ de la crise économique des années trente. « Le système de prestations sociales, les mécanismes de soutien aux revenus des agriculteurs dans ce qui n'était plus une économie à prédominance agricole, l'impact des syndicats sur les salaires, les dépôts de garantie pour les banques (ainsi que pour les caisses d'épargne) et l'engagement keynésien de l'Etat à soutenir résolument l'activité économique - toutes choses qui n'existaient pas après le krach de 1929 - avaient donné à l'économie une forte capacité de résistance », poursuit-il. L'indice du, les importantes et brutales fluctuations du, un mécanisme d'immunisation des portefeuilles, dit, les systèmes automatiques d'achats et de ventes d'actions (. Le 19 octobre 1987 a démontré aux ministres des Finances du G7 qu'il était dangereux de vouloir bloquer un mouvement du dollar. We argue that crashes, in general, themselves are merely a manifestation of uncertainty on stock markets and the high uncertainty due to globalization is mainly responsible for this change. The first contemporary global financial crisis unfolded on October 19, 1987, a day known as “Black Monday” when the Dow Jones Industrial Average dropped 22.6 percent. Using a simple sign test, we report new empirical evidence, taken from both the US and the German stock markets, showing that trading behavior substantially changed around Black Monday in 1987. “Central Bank Tools and Liquidity Shortages.” Federal Reserve Bank of New York Economic Policy Review 16, no. In a statement on October 20, 1987, Fed Chairman Alan Greenspan said, “The Federal Reserve, consistent with its responsibilities as the Nation's central bank, affirmed today its readiness to serve as a source of liquidity to support the economic and financial system” (Carlson 2006, 10). It turned out that before Black Monday investors behaved more as in the momentum strategy; and after Black Monday more as in the contrarian strategy. In the United States, the Dow Jones Industrial Average (DJIA) dropped 22.6 percent in a single trading session, a loss that remains the largest one-day stock market decline in history.2  At the time, it also marked the sharpest market downturn in the United States since the Great Depression. The most common underlying assets include stocks, bonds, commodities, currencies, interest rates and market indexes. The Dow Jones Industrial Average is a closely watched stock price index computed by Dow Jones & Co.