On August 7, 2026, VolRoc recorded 133,762 active prediction markets across Kalshi and Polymarket, holding $1.33B in combined open interest. Day over day, active markets fell 15.5% and open interest was little changed (vs August 6, 2026). Politics & Elections was the largest domain by open interest (37%), ahead of Sports (33%); together they accounted for 70% of all open interest. Kalshi carried 88% of active markets and Polymarket 12%.
Deterministic · template v1 · 2026-08-07
As of 2026-08-07 · 00:00 UTC
Active Markets
133,762
00:00 UTC freeze
Open Interest
$1.33B
Kalshi OI + Polymarket liquidity
Markets Traded · 24h
16,350
with trading activity
Kalshi / Polymarket
88% / 12%
by active-market count
Domain Composition — 12 domains
Sports
59,428
Mixed / Multi-category
42,156
Other
18,115
Politics & Elections
6,229
Entertainment & Culture
2,675
Crypto & Digital Assets
1,380
Economics & Inflation
1,017
Technology & AI
946
Companies & Business
773
Monetary Policy
393
World & Geopolitics
372
Climate & Weather
202
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 = 133,762.
Largest Kalshi Series
Sports — multi-game parlays
46,093
Cross-category multi-markets
42,156
Midterm control
988
Music — artist streams
746
U.S. House races
606
Nextteamnba
494
Nflwins
286
NFL — next team moves
257
Flprimary
207
Nextteammlb
201
Ncaafwins
199
Joinclub
197
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 7, 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 7, 2026.” https://volroc.ai/prediction-markets/2026-08-07/
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