On August 3, 2026, VolRoc recorded 90,176 active prediction markets across Kalshi and Polymarket, holding $1.12B in combined open interest. Day over day, active markets fell 51.0% and open interest fell 22.1% (vs August 2, 2026). Politics & Elections was the largest domain by open interest (44%), ahead of Sports (27%); together they accounted for 70% of all open interest. Kalshi carried 74% of active markets and Polymarket 26%.
Deterministic · template v1 · 2026-08-03
As of 2026-08-03 · 00:00 UTC
Active Markets
90,176
00:00 UTC freeze
Open Interest
$1.12B
Kalshi OI + Polymarket liquidity
Markets Traded · 24h
14,957
with trading activity
Kalshi / Polymarket
74% / 26%
by active-market count
Domain Composition — 12 domains
Sports
47,266
Other
19,150
Mixed / Multi-category
9,305
Politics & Elections
6,440
Entertainment & Culture
2,608
Crypto & Digital Assets
1,369
Companies & Business
1,059
Economics & Inflation
992
Technology & AI
983
Monetary Policy
389
World & Geopolitics
372
Climate & Weather
167
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 = 90,176.
Largest Kalshi Series
Sports — multi-game parlays
31,143
Cross-category multi-markets
9,305
Midterm control
951
Music — artist streams
747
U.S. House races
605
Nextteamnba
487
Nflwins
277
NFL — next team moves
257
Nextteammlb
210
Flprimary
206
Joinclub
184
Ncaafwins
179
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 3, 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 3, 2026.” https://volroc.ai/prediction-markets/2026-08-03/
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