[en]We compare the reaction of the Paris bourse to the US crashes during both the 2008 and the 1929 crises. We constitute a new dataset of daily French stock prices from February 1929 to March 1930 that we combine to the already existing daily series of the Dow Jones. We also use newspapers and minutes from the Banque de France and from the Paris Stock Exchange’s brokers syndicate in order to confront quantitative data with historical narratives. We finally run contagion tests in both periods, using adjusted correlation coefficients to test for pure contagion. In 1929, the Paris stock market does not exhibit any reaction to the New-York crash. The recent crisis is totally different with a clear contagion of the US crash. This study highlights a significant difference between the two crises and provides strong evidence that the transmission of the Great Depression used other channels than stock markets.[/en]