TLDR
- Polymarket held the largest share of U.S. branded prediction market search demand from January to August 2026, according to Blask.
- Polymarket’s search share fell from 74.3% to 57.8%, while Kalshi’s rose from 23.1% to 35.8%.
- Kalshi recorded $37.17 billion in August trading volume, compared with $8.16 billion for Polymarket and Polymarket US combined.
- The year’s biggest search spike came on March 2, the day before the first midterm primaries, not during the World Cup.
- Blask has not yet tested whether search share predicts prediction market trading volume.
Polymarket is still the most searched prediction market brand in the U.S., even though Kalshi handles far more trading volume. That is the main finding of new data from iGaming analytics firm Blask.
Blask tracked search demand for prediction markets from January to August 2026. It used a metric called Brand’s Accumulated Power, or BAP, which measures each brand’s share of branded search demand.
Polymarket’s BAP fell from 74.3% to 57.8% over the period. Kalshi’s rose from 23.1% to 35.8%. Together, the two companies held 93.6% of search demand by August, down from 97.4%.
Among smaller rivals, Novig posted the fastest growth in the Blask Index from January to July, rising 64.9%.
Search Share Versus Trading Volume
Trading data shows a different picture. In August, Kalshi recorded $37.17 billion in volume, compared with $8.16 billion across Polymarket and Polymarket US, according to The Block.
Blask said the two numbers measure different things. “Trading volume is a liquidity/execution metric; BAP is an attention metric,” the company said. It added that Polymarket’s lead comes largely from name recognition as the more established global brand.
Kalshi’s search share climbed during the World Cup. Its BAP rose from 18% in May to 29% in June and 36% in July. Polymarket’s fell from 80% to 69%, then to 61%.
Kalshi’s gains were not only the result of Polymarket losing ground. Its Blask Index rose 22.8% from January to July, while the overall prediction market segment shrank by 22%.
Biggest Search Spike Came Before the Primaries
According to Reuters, Kalshi generated about $27 billion in trading volume during the World Cup. TickerTracker put the figure at about $13.8 billion across individual World Cup markets, excluding combo markets.
Pew Research Center, using The Block data, said combined Kalshi and Polymarket volume reached nearly $53 billion in July. Kalshi accounted for about $40.1 billion of that total.
Still, the Blask Index hit its 2026 peak on March 2, the day before the first midterm primaries in Texas, North Carolina and Arkansas. That reading was more than four times a mid-May baseline. The top World Cup reading was about half that level.
Blask said the link to the primaries is based on timing alone. It cannot prove people were searching with election intent.
During the six-week tournament, median daily prediction market search levels were 38% above the four weeks before kickoff. Blask’s traditional U.S. iGaming measure was 2% lower over the same period.
App data showed new users arriving too. Sensor Tower found that in the World Cup’s first three weeks, Kalshi’s average weekly downloads were nearly twice its Super Bowl LX level. Polymarket’s were nearly four times higher.
Blask said much of the World Cup volume likely came from existing users who did not need to search for the brand again. New users can also find the apps through app stores, ads or social media.
Blask says its testing in traditional iGaming found a 95% correlation between search share and market performance. However, the company said it has not yet run a study on whether that relationship holds for prediction market trading volume.
