On June 8, 2026, VolRoc recorded 84,904 active prediction markets across Kalshi and Polymarket, holding $1.52B in combined open interest. Day over day, active markets fell 36.8% and open interest fell 4.9% (vs June 6, 2026). Sports was the largest domain by open interest (44%), ahead of Politics & Elections (29%); together they accounted for 73% of all open interest. Kalshi carried 90% of active markets and Polymarket 10%.
Deterministic · template v1 · 2026-06-08
As of 2026-06-08 · 00:00 UTC
Active Markets
84,904
00:00 UTC freeze
Open Interest
$1.52B
Kalshi OI + Polymarket liquidity
Markets Traded · 24h
13,110
with trading activity
Kalshi / Polymarket
90% / 10%
by active-market count
Domain Composition — 12 domains
Sports
51,400
Other
12,239
Mixed / Multi-category
9,998
Politics & Elections
5,724
Entertainment & Culture
2,275
Crypto & Digital Assets
1,060
Economics & Inflation
734
Companies & Business
491
Monetary Policy
377
Technology & AI
289
World & Geopolitics
152
Science & Health
88
Climate & Weather
77
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 = 84,904.
Largest Kalshi Series
Sports — multi-game parlays
42,116
Cross-category multi-markets
9,998
Music — artist streams
858
Midterm control
732
U.S. House races
596
California primaries
306
NFL — next team moves
231
Primary vote shares
229
World Cup — games
208
Wcstageofelim
201
Nextteamnba
200
Nbadraftteam
188
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 8, 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 8, 2026.” https://volroc.ai/prediction-markets/2026-06-08/
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