On August 10, 2026, VolRoc recorded 85,396 active prediction markets across Kalshi and Polymarket, holding $1.19B in combined open interest. Day over day, active markets fell 51.9% and open interest fell 17.6% (vs August 9, 2026). Politics & Elections was the largest domain by open interest (42%), ahead of Sports (28%); together they accounted for 70% of all open interest. Kalshi carried 85% of active markets and Polymarket 15%.
Deterministic · template v1 · 2026-08-10
As of 2026-08-10 · 00:00 UTC
Active Markets
85,396
00:00 UTC freeze
Open Interest
$1.19B
Kalshi OI + Polymarket liquidity
Markets Traded · 24h
13,782
with trading activity
Kalshi / Polymarket
85% / 15%
by active-market count
Domain Composition — 12 domains
Sports
38,242
Other
16,883
Mixed / Multi-category
16,303
Politics & Elections
6,284
Entertainment & Culture
2,684
Crypto & Digital Assets
1,361
Economics & Inflation
1,020
Technology & AI
910
Companies & Business
755
Monetary Policy
405
World & Geopolitics
296
Climate & Weather
177
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 = 85,396.
Largest Kalshi Series
Sports — multi-game parlays
28,085
Cross-category multi-markets
16,303
Midterm control
1,022
Music — artist streams
741
U.S. House races
606
Nextteamnba
499
Nflwins
293
NFL — next team moves
228
Rt
225
Ncaafwins
220
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 10, 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 10, 2026.” https://volroc.ai/prediction-markets/2026-08-10/
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