On June 4, 2026, VolRoc recorded 49,813 active prediction markets across Kalshi and Polymarket, holding $1.39B in combined open interest. Day-over-day change is not yet available — this is the archive's first record. Sports was the largest domain by open interest (43%), ahead of Politics & Elections (31%); together they accounted for 74% of all open interest. Kalshi carried 83% of active markets and Polymarket 17%.
Deterministic · template v1 · 2026-06-04
As of 2026-06-04 · 00:00 UTC
Active Markets
49,813
00:00 UTC freeze
Open Interest
$1.39B
Kalshi OI + Polymarket liquidity
Markets Traded · 24h
13,648
with trading activity
Kalshi / Polymarket
83% / 17%
by active-market count
Domain Composition — 12 domains
Sports
22,957
Other
11,946
Politics & Elections
5,874
Mixed / Multi-category
3,432
Entertainment & Culture
2,256
Crypto & Digital Assets
1,141
Economics & Inflation
759
Companies & Business
482
Monetary Policy
376
Technology & AI
272
World & Geopolitics
149
Science & Health
86
Climate & Weather
83
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 = 49,813.
Largest Kalshi Series
Sports — multi-game parlays
13,786
Cross-category multi-markets
3,432
Music — artist streams
855
Midterm control
726
U.S. House races
595
California primaries
351
Primary vote shares
290
NFL — next team moves
231
Primarymov
219
World Cup — games
195
Nextteamnba
188
Nbadraftteam
187
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 4, 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 4, 2026.” https://volroc.ai/prediction-markets/2026-06-04/
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