Kalshi has already surpassed $7.49 billion in notional volume for the week of June 15, surpassing its prior record of $6.38B with Sunday’s session still open. The partial total runs 17.5% above the previous record through just six closed days, putting Kalshi on track for its first $8B-plus week — a likely $8.5B to $8.9B finish out the week, according to DeFi Rate’s volume tracker.
The record total covers six closed UTC trading days, June 15 through June 20, according to DeFi Rate’s prediction markets volume tracker. Sunday, June 21, is in progress as of publication and not yet counted, meaning the final total will climb higher as today’s World Cup slate trades through settlement.
The prediction market is now averaging roughly $1.25 billion per day. A typical Sunday on the current World Cup calendar could add somewhere between $1.0 billion and $1.4 billion, making the $8B+ range a realistic target. That projection is contingent on Sunday’s slate and final settlement.
Either way, the record falls a week after Kalshi crossed $100 billion in lifetime notional volume and recorded its first back-to-back billion-dollar single days. The pace has not let up. Where last week’s $6.38B reflected a 43% jump powered by a single packed sports weekend, this week’s run-rate suggests the World Cup group stage has lifted Kalshi’s baseline daily volume rather than producing a one-off spike.
A UFC fight, not a World Cup match is the biggest market so far
Through the six closed days, a UFC fight is on pace to be the single highest-volume event of the week. The Topuria vs. Gaethje rematch led the board at $50.7 million, ahead of a wall of World Cup group-stage fixtures.
Every one of Kalshi’s ten highest-volume events has been a sports market, consistent with the concentration that has defined the platform’s volume mix throughout 2026. Group stage and the Spain match could reorder this table once the final numbers roll in tonight.
| Rank | Event | WTD volume |
|---|---|---|
| 1 | Topuria vs. Gaethje (UFC) | $50.7M |
| 2 | Mexico vs. Korea Republic | $48.2M |
| 3 | Türkiye vs. Paraguay | $33.7M |
| 4 | Portugal vs. Congo DR | $33.4M |
| 5 | USA vs. Australia | $30.7M |
| 6 | Men’s World Cup Winner | $27.6M |
| 7 | Czechia vs. South Africa | $24.6M |
| 8 | Netherlands vs. Japan | $22.3M |
| 9 | Pereira vs. Gane (UFC) | $21.9M |
| 10 | Belgium vs. Egypt | $21.3M |
Event-level figures group all outcome contracts under each base ticker, drawn from DeFi Rate daily market-volume snapshots, June 15–20. They serve as a decomposition aid and may not reconcile exactly to the trade-tape top-line total.
Polymarket tops $3.4B but trails Kalshi by more than 2-to-1
Polymarket Global is showing $3.41 billion so far in weekly notional through June 20, up 19.6% from the prior week, on 20.2 million transactions. The platform’s top market was a US–Iran permanent peace-deal contract at $131.8 million, followed by a cluster of World Cup match and spread markets.
Both platforms are rising, but Kalshi’s partial week already more than doubles Polymarket’s, extending the lead that has held since the spring.
On a combined basis, the two platforms have traded $10.90 billion so far— also a partial figure with Sunday still open on both sides. The tournament has lifted both on mobile as well, with Kalshi and Polymarket capturing nearly three-quarters of new betting-app installs during the World Cup window.
Polymarket US data remains incomplete for the week. The official Daily Market Report files were posted for only three business dates (June 16, 17, and 19), with files for June 15, 18, 20, and 21 not yet published. The posted subtotal stands at $430.5 million in trade volume, led by World Cup match markets — USA vs. Australia at $7.8 million and Portugal vs. Congo DR at $7.3 million.
Volume figures reflect the notional value (contracts traded × price paid for Polymarket; contracts × $1 face value for Kalshi) and are not directly comparable across platforms. Kalshi top-line uses direct trade-tape data for closed UTC days June 15–20; the week ending June 21 is not yet complete and all totals are partial pending Sunday settlement. Weekly figures are finalized each Sunday and locked.
