On August 11, 2026, VolRoc recorded 154,613 active prediction markets across Kalshi and Polymarket, holding $1.38B in combined open interest. Day over day, active markets rose 81.1% and open interest rose 16.2% (vs August 10, 2026). Politics & Elections was the largest domain by open interest (36%), ahead of Sports (31%); together they accounted for 68% of all open interest. Kalshi carried 92% of active markets and Polymarket 8%.
Deterministic · template v1 · 2026-08-11
As of 2026-08-11 · 00:00 UTC
Active Markets
154,613
00:00 UTC freeze
Open Interest
$1.38B
Kalshi OI + Polymarket liquidity
Markets Traded · 24h
15,683
with trading activity
Kalshi / Polymarket
92% / 8%
by active-market count
Domain Composition — 12 domains
Sports
74,159
Mixed / Multi-category
49,577
Other
16,982
Politics & Elections
6,227
Entertainment & Culture
2,630
Crypto & Digital Assets
1,397
Economics & Inflation
1,019
Technology & AI
908
Companies & Business
751
Monetary Policy
400
World & Geopolitics
296
Climate & Weather
191
Science & Health
76
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 = 154,613.
Largest Kalshi Series
Sports — multi-game parlays
62,546
Cross-category multi-markets
49,577
Midterm control
1,038
Music — artist streams
739
U.S. House races
605
Nextteamnba
500
Nflwins
301
Nfltotal
231
NFL — next team moves
229
Ncaafwins
225
Flprimary
207
Nextteammlb
201
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 August 11, 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 — August 11, 2026.” https://volroc.ai/prediction-markets/2026-08-11/
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