This is a remarkable passage because it resembles closely what one would read in an opinion-based analysis of a market event. The confusing illusion, of course, is that hindsight narratives of this kind could offer anything towards avoiding, let alone preventing, future disasters. In reality, no amount of knowledge of a sandpile system can possibly produce a usable forecast of the size and location of a major avalanche. It may be the same with a stock market crash.
You haven’t seen the effects of *any* of Trumps decisions yet. And Obama’s decisions had virtually zero impact on creating the Great Recession. There wasn’t time. Unless you believe in teleportation, magic, and instantaneous changes to the marketplace and if that’s the case, I’m a nigerian prince building a bridge and boy have I got a business proposition for you…
In France, the main French stock index is called the CAC 40. Daily price limits are implemented in cash and derivative markets. Securities traded on the markets are divided into three categories according to the number and volume of daily transactions. Price limits for each security vary by category. For instance, for the more[most?] liquid category, when the price movement of a security from the previous day's closing price exceeds 10%, the quotation is suspended for 15 minutes, and transactions are then resumed. If the price then goes up or down by more than 5%, transactions are again suspended for 15 minutes. The 5% threshold may apply once more before transactions are halted for the rest of the day. When such a suspension occurs, transactions on options based on the underlying security are also suspended. Further, when more than 35% of the capitalization of the CAC40 Index cannot be quoted, the calculation of the CAC40 Index is suspended and the index is replaced by a trend indicator. When less than 25% of the capitalization of the CAC40 Index can be quoted, quotations on the derivative markets are suspended for half an hour or one hour, and additional margin deposits are requested.[43]

Trying to time a market crash or correction is pretty much impossible, and trying to estimate how much will be lost in that crash is even more difficult. If you had listened to David Haggith’s  doom and gloom warnings back in 2012, you would have missed out on one of the greatest bull runs in history. You also have to realise that permabear “experts” such as Marc Faber exist and that they will constantly make predictions about how the next big market crash is just seconds away. To sum it up: Nobody really knows when it’s going to happen or if it’s worth staying on the sidelines while the market continues to grow upwards. Well, everyone except me of course. I’m 100% certain that a market crash is going to happen in 2018.