I looked back at the 1927 and 1987 crash. All the major indices lost 1/4 to 1/3 of their values in a few days. In today's terms, that is similar to the Dow losing 3000 to 4000 points in a day. This may be a black swan, but if one is not careful, wealth accumulated in a life time can be wiped out in a day. This can happen, for instance, a sudden war and the markets are closed. Do any of you incorporate this rare possibility in your daily trading? If so, how do you do it? I plan to include this contingency plan in most, if not all, my trades.