On July 15, 2026, VolRoc recorded 98,796 active prediction markets across Kalshi and Polymarket, holding $1.45B in combined open interest. Day over day, active markets fell 20.8% and open interest fell 8.2% (vs July 14, 2026). Sports was the largest domain by open interest (37%), ahead of Politics & Elections (31%); together they accounted for 68% of all open interest. Kalshi carried 61% of active markets and Polymarket 39%.
Deterministic · template v1 · 2026-07-15
As of 2026-07-15 · 00:00 UTC
Active Markets
98,796
00:00 UTC freeze
Open Interest
$1.45B
Kalshi OI + Polymarket liquidity
Markets Traded · 24h
18,650
with trading activity
Kalshi / Polymarket
61% / 39%
by active-market count
Domain Composition — 12 domains
Sports
53,696
Other
24,498
Politics & Elections
6,336
Mixed / Multi-category
5,616
Entertainment & Culture
2,542
Crypto & Digital Assets
1,797
Climate & Weather
1,022
Companies & Business
980
Economics & Inflation
793
Technology & AI
489
World & Geopolitics
487
Monetary Policy
424
Science & Health
116
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 = 98,796.
Largest Kalshi Series
Sports — multi-game parlays
29,549
Cross-category multi-markets
5,616
Midterm control
853
Music — artist streams
784
U.S. House races
588
Nextteamnba
434
NFL — next team moves
254
Pgatour
224
Nextteammlb
220
Nflwins
203
Wcaward
193
Flprimary
189
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 15, 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 15, 2026.” https://volroc.ai/prediction-markets/2026-07-15/
Get the daily statistics
A short daily read on the prediction-market universe across Kalshi and Polymarket.
Join the list →