On June 27, 2026, VolRoc recorded 210,209 active prediction markets across Kalshi and Polymarket, holding $2.32B in combined open interest. Day over day, active markets rose 6.1% and open interest rose 2.6% (vs June 26, 2026). Sports was the largest domain by open interest (50%), ahead of Politics & Elections (16%); together they accounted for 67% of all open interest. Kalshi carried 99% of active markets and Polymarket 1%.
Deterministic · template v1 · 2026-06-27
As of 2026-06-27 · 00:00 UTC
Active Markets
210,209
00:00 UTC freeze
Open Interest
$2.32B
Kalshi OI + Polymarket liquidity
Markets Traded · 24h
13,503
with trading activity
Kalshi / Polymarket
99% / 1%
by active-market count
Domain Composition — 12 domains
Sports
158,341
Mixed / Multi-category
32,385
Other
11,423
Politics & Elections
3,787
Entertainment & Culture
2,194
Economics & Inflation
594
Crypto & Digital Assets
542
Companies & Business
322
Monetary Policy
280
Technology & AI
143
Climate & Weather
100
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 = 210,209.
Largest Kalshi Series
Sports — multi-game parlays
148,133
Cross-category multi-markets
32,385
Music — artist streams
804
Midterm control
773
U.S. House races
606
Nextteamnba
357
Mlbhr
263
Wcstageofelim
261
NFL — next team moves
254
Primarymov
240
California primaries
239
Wcmention
234
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 27, 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 27, 2026.” https://volroc.ai/prediction-markets/2026-06-27/
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