How Did the Betting Markets React to Harris' VP Pick?

Although polls usually take days or weeks to reflect the impact of events like Kamala Harris’ pick of Minnesota Gov. Tim Walz as VP, betting markets react almost instantly, providing an initial reaction based on general sentiments. Based on the change in betting odds since the Walz pick, people currently believe he was an electorally positive addition to Harris’ ticket.

The day before Walz was picked, Aug. 5, in the PredictIt betting odds, Trump and Harris were neck-and-neck, with Trump trailing by two points. Harris then jumped to a seven-point favorite the day Walz was picked and nine points the day after, on Aug. 7. Other sites still have Trump ahead, such as the PolyMarket betting odds, which has Trump at a 51% chance to win and Harris at 48%. The current RCP Average of betting odds has Trump 3.3 points ahead, 50.9% to 47.6%, while on August 5, the day before the pick, Trump led by 7.3 points, indicating bettors think Walz makes Harris more likely to win.

The closest states, according to PolyMarket betting odds, are Wisconsin and Pennsylvania. In Wisconsin, Harris holds a slim 2% lead, and in Pennsylvania, they are tied. In the southern swing states of North Carolina, Georgia, Arizona, and Nevada, Trump holds a 10% to 32% lead in the chance to win. In the last swing state of Michigan, Harris has a 60% chance to win, while Trump trails at 40%. With betting markets now incorporating Walz into the odds, the race is still a tossup, with neither candidate holding enough electoral votes to win without Pennsylvania.

These betting results mirror the polling in every state, as in every state where Harris leads in the betting odds, she also leads in the RCP Average. In Pennsylvania, where the race is tied in the odds, Trump leads by 1.8 points in the heads-up RCP Average, but Harris leads by 0.2 points in the five-way average.

The changes in betting odds reflect a snap YouGov poll conducted on Aug. 6 with 2,966 adult respondents, taken after the Walz pick was announced, which indicated that people generally have favorable opinions of Walz if they have any opinion of him at all. The poll found that 32% of people were “very favorable” or “somewhat favorable” of Walz, while 19% were “somewhat unfavorable” or “very unfavorable,” and 40% didn’t have an opinion of him. Among Democrats, 60% had a favorable opinion, and 35% didn’t have an opinion; among independents, 24% had a favorable opinion, and 15% had an unfavorable one.

The poll also found that 59% of Democrats thought Walz was a good or “the best” possible pick Harris could have made for VP, while only 2% thought it was a poor choice. Independents also approved more than they disapproved, with 25% saying it was a positive pick and only 13% saying it was a bad one.

In the latest Economist/YouGov poll conducted from Aug. 4-6, 21% of respondents said they had a favorable opinion of Walz, and 15% had an unfavorable opinion, with the majority, 65%, saying they didn’t know what their opinion was.

Both candidates now have their presumptive tickets, leaving the Democratic National Convention and a possible debate in early September as the last expected major events in the election season. With the two candidates currently neck-and-neck, the next month will likely determine whether there will be a clear favorite going into the November election.