On July 23, 2026, VolRoc recorded 155,813 active prediction markets across Kalshi and Polymarket, holding $1.47B in combined open interest. Day over day, active markets fell 14.4% and open interest fell 3.4% (vs July 22, 2026). Sports was the largest domain by open interest (41%), ahead of Politics & Elections (32%); together they accounted for 72% of all open interest. Kalshi carried 75% of active markets and Polymarket 25%.
Deterministic · template v1 · 2026-07-23
As of 2026-07-23 · 00:00 UTC
Active Markets
155,813
00:00 UTC freeze
Open Interest
$1.47B
Kalshi OI + Polymarket liquidity
Markets Traded · 24h
21,631
with trading activity
Kalshi / Polymarket
75% / 25%
by active-market count
Domain Composition — 12 domains
Sports
97,118
Other
27,910
Mixed / Multi-category
14,541
Politics & Elections
6,427
Entertainment & Culture
2,621
Crypto & Digital Assets
1,945
Companies & Business
1,200
Climate & Weather
1,157
Technology & AI
970
Economics & Inflation
868
World & Geopolitics
511
Monetary Policy
463
Science & Health
82
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 = 155,813.
Largest Kalshi Series
Sports — multi-game parlays
73,932
Cross-category multi-markets
14,541
Midterm control
887
Music — artist streams
771
U.S. House races
595
Nextteamnba
453
NFL — next team moves
254
Nextteammlb
225
Nflwins
225
Flprimary
194
Mlbhr
170
Albumequiv
163
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 July 23, 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 — July 23, 2026.” https://volroc.ai/prediction-markets/2026-07-23/
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