Hillary Clinton’s contract prices are up 8 percent in volatile post-debate overnight trading on the Iowa Electronic Markets, while contract prices for Donald Trump are down 3 percent.

As of 9 a.m. CDT Tuesday, Clinton was trading at 70.5 cents, which means traders believe she has a 70.5 percent probability of winning the popular vote in the Nov. 8 election. That number is up from the 65.3 cents she traded at in the hours leading up to the start of Monday’s debate.

Trump was trading at 31.8 cents Tuesday morning, down from the 32.8 cents he traded at before the start of the debate.

The Iowa Electronic Markets is operated by the University of Iowa’s Tippie College of Business as a real-money futures prediction market that allows traders invest up to $500.

Market prices have moved significantly since the debate ended, with Clinton at one point selling for as high as 79 cents and Trump for as low as 28.5 cents. Trading was moderate Monday, with more than 3,300 contracts bought and sold.

On the IEM’s Vote Share market, which tracks the percentage of the two-party vote that traders believe each candidate will receive, Clinton’s contract is trading for 53.9 cents, which means traders believe she will get 53.9 percent of the popular vote. Trump is selling for 47.4 cents. Those figures were unchanged by the debate.

Begun in 1988, the IEM is a research and teaching tool that has achieved an impressive prediction record, substantially superior to alternative mechanisms such as opinion polls. Markets like the IEM have been significantly more accurate than traditional tools in predicting outcomes ranging from political election results to movie box office receipts.

The latest contract prices can be found at https://tippie.biz.uiowa.edu/iem.