On October 7, 2026, VolRoc recorded 279,670 active prediction markets across Kalshi and Polymarket, holding $2.08B in combined open interest. Day over day, active markets rose 19.3% and open interest rose 149.0% (vs October 6, 2026). Politics & Elections was the largest domain by open interest (26%), ahead of Sports (19%); together they accounted for 46% of all open interest. Kalshi carried 91% of active markets and Polymarket 9%.
Deterministic · template v1 · 2026-10-07
As of 2026-10-07 · 00:00 UTC
Active Markets
279,670
00:00 UTC freeze
Open Interest
$2.08B
Kalshi OI + Polymarket liquidity
Markets Traded · 24h
21,237
with trading activity
Kalshi / Polymarket
91% / 9%
by active-market count
Domain Composition — 12 domains
Mixed / Multi-category
213,621
Other
25,958
Sports
22,981
Politics & Elections
8,555
Entertainment & Culture
2,857
Crypto & Digital Assets
1,364
Economics & Inflation
1,015
Companies & Business
870
Technology & AI
838
World & Geopolitics
698
Monetary Policy
510
Climate & Weather
322
Science & Health
81
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 = 279,670.
Largest Kalshi Series
Cross-category multi-markets
190,367
KXMVECROSSCATEGORY0
23,254
Midterm control
1,775
Votegeneral
1,517
U.S. House races
671
Music — artist streams
590
Ncaafspread
453
Nextteamnba
427
Midtermvoteturn
425
Nflwins
412
Ncaafwins
406
Ncaaftotal
292
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 October 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 — October 7, 2026.” https://volroc.ai/prediction-markets/2026-10-07/
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