Election trading expands at Kalshi as South Carolina delivers an upset

Kalshi’s election markets generated more than 2.5 billion dollars in trading volume this cycle, according to Reuters reporting carried by DevDiscourse. That compares with 1.3 billion dollars during the 2024 cycle, which included the presidential race.

The figures put this cycle’s election-market turnover at more than twice the 2024 level. They measure trading activity, rather than the accuracy of the probabilities those markets produced.

Accuracy claim meets a notable exception

A person familiar with the matter put Polymarket’s election forecast accuracy at about 98 percent, according to Reuters via DevDiscourse. The supplied reporting does not explain how that figure was calculated, limiting what readers can infer about the performance measure.

South Carolina provided a notable miss. Democrat Annie Andrews defeated Republican Darline Graham, even though markets assigned Graham about a 70 percent chance of winning late on Tuesday.

That result illustrates the distinction between a favored outcome and a certain one. A probability of about 70 percent still leaves room for defeat; the upset alone does not establish whether the market’s probability was poorly calibrated.

What it means for prediction markets

• Activity increased substantially: Kalshi’s election-market volume exceeded 2.5 billion dollars, against 1.3 billion dollars in the 2024 cycle.
• The accuracy claim needs context: Polymarket’s roughly 98 percent figure comes from a person familiar with the matter, without a calculation method in the supplied reporting.
• Favorites can lose: Andrews’ victory over Graham is a reminder that market probabilities express uncertainty, not guaranteed outcomes.