I follow regularly three prediction markets: Election Betting Odds, Iowa Electronic Markets, and PredictWise. On Election Betting Odds, his probability has dropped 8.1 percentage points over the last day (to 17.7%). He is down to 13% on PredictWise (he was over 20% a couple of days ago). On the Iowa site, he is down to just above 20% from 25% yesterday.