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%