On July 13, 2026, VolRoc recorded 93,176 active prediction markets across Kalshi and Polymarket, holding $1.42B in combined open interest. Day over day, active markets fell 71.9% and open interest fell 36.9% (vs July 12, 2026). Politics & Elections was the largest domain by open interest (31%), ahead of Sports (31%); together they accounted for 62% of all open interest. Kalshi carried 58% of active markets and Polymarket 42%.
Deterministic · template v1 · 2026-07-13
As of 2026-07-13 · 00:00 UTC
Active Markets
93,176
00:00 UTC freeze
Open Interest
$1.42B
Kalshi OI + Polymarket liquidity
Markets Traded · 24h
18,195
with trading activity
Kalshi / Polymarket
58% / 42%
by active-market count
Domain Composition — 12 domains
Sports
47,702
Other
25,068
Politics & Elections
6,280
Mixed / Multi-category
4,473
Entertainment & Culture
2,660
Crypto & Digital Assets
2,183
Climate & Weather
1,216
Companies & Business
1,098
Economics & Inflation
950
World & Geopolitics
503
Technology & AI
493
Monetary Policy
429
Science & Health
121
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 = 93,176.
Largest Kalshi Series
Sports — multi-game parlays
24,916
Cross-category multi-markets
4,473
Midterm control
839
Music — artist streams
787
U.S. House races
589
Nextteamnba
427
NFL — next team moves
254
Nextteammlb
219
Nflwins
201
Flprimary
189
Wcaward
187
Pgatour
175
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 13, 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 13, 2026.” https://volroc.ai/prediction-markets/2026-07-13/
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