CHF has gone up 130% under the weak dollar policies of GW Bush, Bernanke and Obama over the past ten years, as can be seen in the Fig. 1. This is in sharp contrast to the strong dollar policy of Reagan.
Overshoot, mean reversion, and undershoot are all part of the behavior of financial markets dominated by speculators. The Forex market is the domain of speculators big, e.g., George Soros, and small and govt manipulators. Fig. 2 shows overshoot and undershoot of the CHF w.r.t. the USD over the past 40 years.
What would bring CHF down (as it has been the case several times in the past)? Lest people forget Switzerland relies very heavily on imports and exports, i.e., global trade. Not only is CHF grossly over-valued compared to the USD, it is also over-valued compared to the Euro, its the largest trading partners.
The current bearish sentiment against the US dollar is the result of massive global imbalances caused primarily by economic and financial manipulators in the US over the past two decades. This has allowed Americans to live beyond their means year after year after year. All such things always come to an end, i.e., reality forces them to an end. The current fight over the debt ceiling in the US is recognition of the fact that one could not continue on a certain path of kicking the can down the road forever. The same applies for the global imbalances.
Some economic or political event would trigger massive adjustments in the economies of various countries and that would inevitably lead to a massive rally in the US dollar when Americans would be forced to live within their means by lowering their consumption, especially, consumption of foreign goods and services. It could happen sooner than most are prepared for.