Recent polling averages and race rating adjustments have driven Republican probabilities for House control in the 2026 midterms to the low single digits on major prediction markets. Cook Political Report shifted more than a dozen House contests toward Democrats in late October, citing a widening battlefield and an 8-point national generic ballot advantage for Democrats. These updates, combined with consistent trader positioning on Polymarket and Kalshi, placed Republican odds near 6 percent as of October 31. The November 3 election remains the decisive event, with outcomes in roughly 18 toss-up districts and turnout patterns in battleground states able to alter final seat totals before resolution.