In the financial sector， crashes probably represent the most striking eventsamong all possible extreme phenomena， with an impact and frequency thathas been increasing in the last two decades. Consider the worldwidecrash in October 1987 which evaporated more than one thousand billion dol-lars in a few days or the more recent collapse of the internet bubble in whichmore than one-third of the world capitalization of 1999 disappeared afterMarch 2000. Finance and stock markets are based on the fluid convertibilityof stocks into money and vice versa. Thus， to work well， money is requestedto be a reliable standard of value， that is， an effective 8tore of value， hence theconcerns with the negative impacts of inflation.