Less than a week ago, Donald Trump appeared to be a strong contender on prediction markets as polling data trended in his favor. However, this is no longer the case.
With only two days remaining until Election Day, PredictIt now places Kamala Harris in the lead, pricing her winning contract at 54 cents on Sunday, up from 46 cents on Tuesday and 42 cents a week earlier. In contrast, Trump’s winning contract is currently at 51 cents, having declined from 60 cents on Tuesday.
According to Kalshi, Trump’s odds of victory stood at 51% on Sunday, with Harris at 49%. This marks a significant drop from Tuesday, when Trump’s odds were as high as 64.6% and Harris’s were at 35.4%.
The new IBKR Forecast Trader from Interactive Brokers reported Trump’s odds of winning at 54% on Sunday, a decrease from 68% on Tuesday. Harris’s odds climbed as high as 54% on Sunday before slightly declining to 48% later in the day, both up from 37% on Tuesday.
The significant surge for Harris on IBKR prompted Thomas Peterffy, founder and chairman of Interactive Brokers, to issue a statement on Friday. He remarked on the surprising 8-point increase in one day, supported by trading volume totaling approximately $40 million.
Skeptics have warned that prediction markets can be susceptible to manipulation, but Peterffy noted that such actions are illegal and unlikely to have influenced Harris’s sudden rise on IBKR. Instead, he credited the shift to news coverage events.
Thomas Miller, a data scientist at Northwestern University, indicated that a significant turning point occurred during Trump’s rally at Madison Square Garden last Sunday. During the event, comedian Tony Hinchcliffe sparked backlash by derogatorily referring to Puerto Rico, which persisted throughout the week.
Miller recently informed Fortune that since the rally, Trump has experienced a significant decline, potentially leading to Harris’s election victory.
Supporting Harris’s prospects was a closely observed Des Moines Register/Mediacom Iowa Poll conducted by Selzer & Co. This poll revealed Harris leading Trump 47% to 44% among likely voters.
This represents a reversal from September when the same poll indicated Trump held a 4-point lead over Harris, suggesting increasing support for Harris in other regions as well, including the pivotal swing states of Wisconsin, Michigan, and Pennsylvania.
On Sunday morning, the New York Times/Siena College poll of battleground states indicated that while the race remains close, last-minute deciders are leaning toward Harris.
These developments follow a month of predominantly favorable polling data for Trump, despite over 70 million voters having already cast their ballots.
The latest polling analysis from 538 assigns Trump a 53-in-100 chance of winning the election compared to 47-in-100 for Harris, maintaining the same probabilities as a week prior.
José Torres, senior economist at Interactive Brokers, noted on Friday that a Republican sweep of the White House, Senate, and House of Representatives is still narrowly favored in the IBKR forecasting model.
