Kalshi midterm accuracy hits 98% of settled races

Prediction markets are publishing their midterm report cards while a handful of races remain open. Kalshi midterm accuracy hit 98% on the venue's own recap, with combined favorites correctly calling 479 of 487 settled races after a cycle that cleared more than $2.5 billion of volume.

What happened

Kalshi's November 4 midterms recap said combined favorites went 479 for 487, a 98% hit rate, against more than $2.5 billion of midterm-cycle volume compared with $1.3 billion in the 2024 cycle. House control priced to 99% at 8:10 p.m. ET and Senate control to 99% at 9:00 p.m. ET on election night, while Alaska Senate and Mississippi Senate were still unresolved at the time of the post.

KuCoin's November 5 market report added a Polymarket scoreboard: 419 of 426 settled favorites, or 98.4%, with 78 races still unsettled. Across 10 key races, markets hit 99% a median of about 31 minutes before CNN, Fox or AP calls, and Kalshi's November 3 volume was about $729 million — roughly three times its 2024 election single-day peak.

The dual-venue picture is consistent even if the denominators differ: both Kalshi and Polymarket favorites cleared the mid-98% range on settled races while a long tail of local contests stayed open for certification.

Why it matters

Accuracy claims are how prediction venues pitch themselves against polls and cable desks. Our Democratic sweep prediction markets piece tracked chamber contracts racing to near-certainty; Kalshi midterm accuracy at 98% is the ex-post validation of that pricing speed.

Lead time versus TV calls also matters for traders. The election day midterm odds tape already leaned Democratic into the vote; a median 31-minute head start at 99% on key races is the practical edge venues sell to newsrooms and funds alike.

Volume scaling from $1.3 billion in 2024 to more than $2.5 billion this cycle also changes liquidity: these markets are no longer niche curiosities when a single Kalshi day can clear about $729 million.

Unresolved races keep a caveat on the victory lap. Alaska Senate and Mississippi Senate were still open in Kalshi's own post, and KuCoin counted 78 unsettled races on the Polymarket side, so the final favorites ratio can still drift by a point either way. Even so, the election-night path to 99% on House and Senate control hours before midnight Eastern is the operational takeaway for newsrooms that now treat venue odds as a first draft of the map.

What's next

Market participants will also weigh liquidity conditions into the U.S. afternoon, because thin books can exaggerate follow-through moves even when the fundamental catalyst is already in the price. Desk commentary after the print emphasized verifying primary-source figures against secondary wraps before treating any single headline number as settled. That verification habit matters when multiple outlets round the same tape differently across time zones.

Watch the remaining unresolved Senate races and whether final certifications change any of the 479/487 favorites. Kalshi's midterms recap is the primary source for the Kalshi midterm accuracy print.

A clean finish above 97% after Alaska and Mississippi resolve would harden the marketing claim into a full-cycle statistic.

Regulators and exchanges will separately study whether that volume growth brings more surveillance obligations as political contracts scale into the multi-billion-dollar range.