Kamala Harris likelihood to win presidential election

The increase in prediction market price from $0.43 to $0.52 between August 1 and August 13, 2024 for whether Kamala Harris will win the 2024 presidential election, likely reflects several key developments. Most notably, Harris officially secured the Democratic nomination on August 5, marking a significant milestone in her campaign. This formal recognition solidified her status as the Democratic Party's standard-bearer, which likely bolstered confidence among her supporters and speculators in the prediction markets. Additionally, the selection of Minnesota Governor Tim Walz as her running mate on August 6 may have also played a role. Walz is viewed as a strategic choice capable of appealing to both the progressive base and moderate voters, potentially improving Harris's electoral prospects.

Moreover, Harris's recent campaigning efforts, particularly in battleground states, have shown positive momentum. A new poll released on August 10 indicated that Harris had taken the lead in key "Blue Wall" states, which are crucial for winning the Electoral College. This polling data, combined with the ongoing support from the Democratic establishment and her focus on uniting the party, may have driven increased confidence in her chances of winning the election, thus contributing to the rise in her prediction market price.

Winner of the popular vote for US elections in November

The Polymarket prediction for whether Kamala Harris wins the popular vote significantly increased from $0.48 to $0.67 between July 23 and August 5, 2024. This can be attributed to a series of strategic and impactful events. On July 23, Kamala Harris officially launched her presidential campaign with a rally in Wisconsin, where she emphasized themes of freedom, voting rights, and gun safety. Her powerful speeches resonated with many voters and helped to solidify her position as a strong contender against Donald Trump. This period also saw her gaining critical endorsements from key Democratic leaders and robust fundraising efforts, which bolstered her campaign's visibility and credibility​​.

Additionally, Harris’s performance in the polls contributed to the increased market confidence. During this time, several polls showed Harris either leading or closely trailing Trump in key battleground states. This positive polling data, combined with Trump’s controversial decision to withdraw from a scheduled debate with Harris and his subsequent derogatory remarks, may have further swayed public opinion in her favor. The combination of strategic campaigning, strong endorsements, effective fundraising, and favorable polling likely drove the significant rise in Harris's prediction market value​​.

Chances of a Republican sweep decrease as Kamala Harris named new Democratic presidential nominee

Between July 21 and July 29, 2024, the Polymarket prediction market saw a notable decline in the probability of the Republican Party winning the Presidency and both houses of Congress, dropping from $0.41 to $0.33. A key event driving this shift was President Joe Biden's announcement on July 21 that he would not seek re-election, citing age-related concerns after a poor debate performance. This decision boosted Vice President Kamala Harris as the Democratic front-runner, potentially unifying Democratic support and affecting the Republican prospects​ .

Additionally, during this period, polling data revealed that Harris was performing competitively against former President Donald Trump, who is the presumptive Republican nominee. For instance, a Forbes/HarrisX poll from late July showed Trump leading Harris by a narrow margin of 51% to 49%, indicating a tight race that could influence market perceptions of the overall Republican chances. These developments likely contributed to the decreased confidence in a Republican sweep in the 2024 elections​.