That article forgets to mention that the Trump's odds of winning are highest ever:
so as of 05/06/2016 his odds are about 25%+, and that's mostly among European "investors", which tend to be a bit more left leaning than the US... combine that with general "underdog bias" and his real odds of winning are probably closer to 1/3rd...
those are pretty decent odds I think, certainly far from "that nutjob will never make it past the primaries" that people were saying just few months ago...