Well, the markets didn't crash today and the conservatives point to that as proof nothing bad will happen if they destroy the government. Of course the markets don't believe the Republicans will really allow it to happen or if they do the markets still believe that Obama will save the country by invoking the 14th amendment.
But just because the markets didn't crash today doesn't mean they won't. The markets are in a bubble, the economy is hollowed out too much to support the markets. Predicting a market crash is impossible, much like predicting a forest fire. You can expect fire when there is a drought but you don't know when or if it will rain first. You know the longer fire conditions exist the more likely that somebody stupid or malicious will start a fire. There are plenty of rightwingers who like to play with matches.