Kalshi's $454M crypto volume week flips Polymarket's early-2026 lead
Kalshi recorded $454 million in crypto-themed event contract volume in a single week, flipping Polymarket's early-2026 dominance in the category. At the start of the year, Polymarket led crypto prediction market segment; Kalshi's surge now gives it more than 60% of the US crypto prediction contract market, according to a DiarioBitcoin report shared on Threads. The shift came over roughly five months. Broader weekly data from DeFi Rate for the week of May 18 shows prediction market platforms combined for $5.6 billion in notional volume, with Kalshi capturing 71% ($3.99 billion, up 3% week-over-week) and Polymarket falling 15% to $1.65 billion. For Q1 2026 overall, Kalshi processed $33 billion versus Polymarket's $26.17 billion, per Pluang data. The two platforms' weekly trading volume together hit $6 billion, according to Exploding Topics.
Polymarket's eight-month volume growth streak ended less than two weeks ago, stripping its main investor narrative right as Kalshi's $1 billion Series F fundraising window demands proof that regulated markets can capture offshore liquidity. Any sustained crypto share loss threatens Polymarket's ability to match Kalshi's valuation premium, which Investing.com attributes partly to weaker US regulatory positioning.
Kalshi's volume leadership joins a running streak of three platform-specific records this month, even as regulatory and competitive pressure mounts from a new Hyperliquid events vertical, a House insider-trading probe, and the NHL becoming the second league to sign an integrity memo with CFTC-registered exchanges.