French stock market volatility observed over the last 150 years presents a huge instability. From a very low level before the First World War, it shows a continuous increase during the inter-war period. Despite peace and economic stability, volatility has never converged to levels seen pre-1914....

Stock market crashes are crucial as a large part of the final value of any stock market index is realized during these extreme events. But, the same price variation in percentage does not have the same impact in a stable financial environment as in a highly volatile period. To identify crashes...