Mississippi Senate prediction markets drew more than $50 million as count stayed unresolved

More than $50 million had been wagered across Kalshi and Polymarket on Mississippi’s still-uncalled U.S. Senate race by Nov. 11, even as Democrat Scott Colom held a narrow lead over Republican incumbent Cindy Hyde-Smith in the ballot count.

The trading covered contracts on the winner, the winning party and the margin of victory. At 11:35 a.m. that day, Colom led by about 2,900 votes, according to the Clarion Ledger. County certification deadlines meant Mississippi’s results could at that point have remained unresolved until Friday, Nov. 13.

As we reported on Nov. 4, Kalshi’s pricing had already swung abruptly toward Colom after late returns put him ahead. By Nov. 11, Kalshi put his chance of winning at 99.5% and projected a Democratic victory margin of 0.6 percentage points; Polymarket gave him about a 99.4% chance.

The shift was a sharp reversal in prediction-market odds. Kalshi had put Hyde-Smith’s implied probability at 87% to 90% through October, with Colom below 14%, and still showed Hyde-Smith at 85% on Nov. 1. Its market flipped at midnight on Nov. 4.

Polymarket had similarly kept Hyde-Smith in the high-80% to low-90% range from May through Election Day. Colom’s price jumped to 79% there on Nov. 4, while Hyde-Smith fell to 18.9%; by Nov. 11, Hyde-Smith’s implied chance was 0.4%.

The platforms’ published activity figures differed by contract and reporting time. Kalshi’s total for race-related contracts was above $30.2 million, including nearly $1.2 million on the party outcome, while Polymarket’s main outcome contract had about $6.5 million in wagers and its margin contracts about $50,000. Action Network listed Kalshi volume at $42.6 million, up roughly $1.7 million from the previous day.

An Associated Press-based count put Colom ahead by 2,990 votes. Polymarket’s tracker showed Colom ahead 470,266 to 467,183, with 95% of the vote counted. Kalshi’s own feed showed a slightly different tally, with 97.8% counted and a 2,990-vote Colom lead. More than 8,000 outstanding affidavit ballots in Democratic-leaning Hinds County were expected to be uploaded that Wednesday, although about 24% of affidavit ballots had been rejected statewide.

Hyde-Smith said thousands of votes remained in question and that she was confident. Colom said she should accept the voters’ will, while saying he was prepared to litigate. Mississippi had no recount law, and state law did not clearly specify a procedure for challenging a general-election result for a state office.

Prediction-market prices reflected trading rather than an official result. Users buy yes or no shares priced from 1 to 99 cents; a correct share pays $1, while an incorrect one loses its purchase price.