Two days before the Montana Special Election, gamblers on the website were giving Greg Gianforte 80 to 20 odds to win, but after assault charges were filed against Gianforte, his stock dropped significantly.

"Yesterday the likelihood of [Gianforte] winning the election went from 81 all the way down to 34 cents, which was the low, at around 1:35 A.M.Eastern Time (11:35 P.M. MTN), but by noon on election day he was back up to 64 percent," said PredictIt spokeswoman Brandi Travis.

PredictIt runs these types of polls for all kinds of elections, but Travis says it is rare to see that kind of flux.

"We have seen it before, but it is usually when a major shake-up like this happens. It is a major event and I think that they started to back-out because of the information coming in about how many early votes were in. There is a lot of movement on that market, and there has been, of course, leading up to the election, but even more so after the event."

Each Predict it share costs a dollar based on bidder's expectations about who will win. A separate Predict It market was measuring how close the Montana race would be and by noon on Election Day the big money was on a final vote to be within just five percent.

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