Blask: Kalshi leads Polymarket as US prediction markets surge 4x

Prediction markets traded more in October than in any month before, and most of that volume went through Kalshi. US search demand followed, ending a lead Polymarket had held since May 2024. Kalshi held 51.8% of BAP (brand accumulated power, a brand’s share of search demand among tracked prediction market brands) in the United States in October, against 37.5% for Polymarket, according to Blask data. Kalshi’s Blask Index (a brand search demand metric built from Google Keyword Planner and Google Trends signals) rose 153% month over month, while Polymarket’s slipped 3%. Over the same month, prediction markets traded a record $123.3B in notional volume, and Kalshi accounted for about 80% of it, TokenPost reported. Kalshi took the lead in October after trailing Polymarket every month of the past year. BAP, %, prediction market brands, United States, October 2025 – October 2026. Polymarket led US prediction market search every month from May 2024 to September 2026. Kalshi last ranked first in April 2024, when Blask tracked only 12 prediction market brands in the country. The gap was widest around the 2024 presidential election: in October 2024, Polymarket held 88% of BAP and Kalshi 8.5%. Kalshi’s share stayed below 30% for most of the next two years and only began to close in on its rival in July 2026. Football drove the surge The jump follows the sports calendar rather than a single announcement. Kalshi set a company record of $19.03B in contract volume in the week of October 5–11, with parlay-style combo contracts making up about 70% of it, according to Predictable. For the full month, football parlays accounted for 67.6% of Kalshi’s volume, per TokenPost. Search demand built up through the month. Kalshi’s daily Blask Index rose about three-quarters between the first and last weeks of October, and the brand first out-searched Polymarket on a single day on October 19. That came a week before the NBA signed a memorandum of understanding with the CFTC and named both companies its preferred prediction market exchanges on October 26. Kalshi entered the football season with an NFL-timed ad campaign featuring Marshawn Lynch and Pete Sampras, launched on September 10. The monthly lead does not yet look settled. On a daily basis, the two brands swapped first place several times in the second half of October, and Polymarket led on every day from October 25 to 30. It also drew more searches than Kalshi on November 3 and 4, around the US midterm elections — the type of event that built its lead in 2024. Bottom line Kalshi turned a record month of sports trading into the top spot in US prediction market search, ending Polymarket’s 29-month run. Whether the lead holds will be decided in November, when election-driven demand, where Polymarket has been strongest, overlaps with the busiest stretch of the football season. Midterm results drive US prediction market search to a x4 spike Americans searched for prediction markets more on the day after the midterms than on any day since spring. The record for 2026 still belongs to the first week of the Iran war. On November 4, as Democrats secured majorities in both the House and the Senate, US search demand for prediction market brands reached about four times its October daily average, according to Blask Index (a brand search demand metric built from Google Keyword Planner and Google Trends signals). Polymarket drew 51.5% of that day’s demand and Kalshi 47.5%, and for Kalshi it was the strongest day of the year. Daily Blask Index, all tracked prediction market brands, United States, January 1 – November 8, 2026. An election night that moved money and searches Trading followed the same calendar. Between midnight ET on November 3 and 6 a.m. ET on November 4, Kalshi traded $127.4M across 11 midterm markets, more than four times Polymarket’s $30.6M, according to Gaming America. Polymarket priced a Democratic House at 99% at 8 p.m. ET on November 3, more than five hours before the Associated Press called it. Upsets also fed attention: on election night, at least $1M traded on a Kalshi market backing Texas Gov. Greg Abbott, who lost to Democrat Gina Hinojosa, CNBC reported. Semafor estimates that trading on down-ballot races grew nearly fivefold from the 2024 cycle, to $1.8B. Search split almost evenly between the two leaders, even though Kalshi carried about 80% of the midterm trading volume. Not the year’s highest day The record for 2026 was set on March 2, when demand ran about 7% above the November 4 level. That surge came after the US-Israeli strikes on Iran: geopolitics wagers on Polymarket reached $425.4M in the week ending March 1, up from $163.9M a week earlier, Bloomberg reported. Polymarket alone took 87% of US prediction market search on March 2. Scrutiny followed within days, including Reuters reports on insider trading concerns around Iran bets and a bill from congressional Democrats to rein in the platforms. The March spike also lasted longer. Between March 2 and March 6, four days came close to the November 4 level, while the midterm surge held for a single day. The third-largest peak of the year, Super Bowl LX on February 8, was split almost evenly between Polymarket and Kalshi. Bottom line The midterms showed that a US election can still push prediction market search to a multiple of its usual level, and that Kalshi now competes with Polymarket for that attention on equal terms. A war, not an election, set the 2026 high, and one that played almost entirely in Polymarket’s favor. The open question is which of the two will capture the next breaking news event of that size.