On June 26, 2026, VolRoc recorded 198,149 active prediction markets across Kalshi and Polymarket, holding $2.26B in combined open interest. Day over day, active markets fell 6.3% and open interest fell 0.9% (vs June 25, 2026). Sports was the largest domain by open interest (49%), ahead of Politics & Elections (17%); together they accounted for 66% of all open interest. Kalshi carried 99% of active markets and Polymarket 1%.
Deterministic · template v1 · 2026-06-26
As of 2026-06-26 · 00:00 UTC
Active Markets
198,149
00:00 UTC freeze
Open Interest
$2.26B
Kalshi OI + Polymarket liquidity
Markets Traded · 24h
12,717
with trading activity
Kalshi / Polymarket
99% / 1%
by active-market count
Domain Composition — 12 domains
Sports
134,949
Mixed / Multi-category
43,752
Other
11,426
Politics & Elections
3,780
Entertainment & Culture
2,159
Economics & Inflation
602
Crypto & Digital Assets
585
Companies & Business
292
Monetary Policy
274
Technology & AI
143
Climate & Weather
89
World & Geopolitics
67
Science & Health
31
Venue-agnostic subject taxonomy from Kalshi series prefixes and
Polymarket title keywords. A residual Other bucket is reported honestly.
Yes-price across both venues, 10 buckets from 0 to 100. n = 198,149.
Largest Kalshi Series
Sports — multi-game parlays
125,604
Cross-category multi-markets
43,752
Music — artist streams
814
Midterm control
769
U.S. House races
606
Nextteamnba
345
Wcstageofelim
257
NFL — next team moves
254
Primarymov
240
California primaries
239
Wcmention
225
Primary vote shares
222
Kalshi market families (Polymarket is not series-structured).
About & Citation
This is the fixed-hour (00:00 UTC) state of every active market on
Kalshi and Polymarket for June 26, 2026. The live
Observatory
shows the current diurnal value; this record is immutable. Open interest combines Kalshi
open interest with Polymarket USD liquidity as comparable USD magnitudes. Sources: Kalshi, Polymarket.
How to cite
“VolRoc Prediction Market Archive — June 26, 2026.” https://volroc.ai/prediction-markets/2026-06-26/
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