Texas Political Volume at Kalshi Focusing on Cornyn-Paxton Runoff

Author ... Derek Helling
Derek Helling

Derek Helling is a journalist who has covered the gaming industry for many publications since 2018. His coverage emphasizes the intersections of gambling with the business of entertainment, the evolution of the legal lan...

Texas political markets have reached $24.2 million of trading volume on Kalshi, but less than $200K in open interest separates Paxton from Cornyn.

As May 26 races for federal and state positions heat up in Texas, the trading action at Kalshi has picked up as well. Markets covering several partisan Texas primaries have drawn more than $24.2 million in cumulative volume.

While markets for November’s general elections are available as well, most of the volume has landed on a handful of primary runoffs. The markets are indicating a runaway favorite in perhaps the most important federal race between John Cornyn and Ken Paxton, according to DeFi Rate’s aggregation of Kalshi data via public market API and exchange data feeds.

$14.8 million on “Who will be Republican nominee for Senate in Texas?”

Almost $14.8 million of the more than $24.2 million in volume at Kalshi has been traded on contracts pertaining to the primary runoff between Cornyn and Paxton. 

The Texas Republican Senate nominee market shows Paxton as a heavy 95.2% favorite as of Monday morning, thanks in large part to a late endorsement from President Donald Trump on May 19.

The volume gap is wider than the open-interest gap. Paxton leads Cornyn by about $1.35 million in cumulative volume, but by only about $168,000 in current open interest.

ContractVolume (USD)Open interest (USD)
Will Ken Paxton be the Republican nominee for Senate in Texas?8,094,708.671,850,380.68
Will John Cornyn be the Republican nominee for Senate in Texas?6,741,785.101,682,878.02

Related prop markets for this race have also seen significant but lower-volume action. Kalshi has 37 related contracts that, with cumulative volume drawing over $2.4 million in trades through Monday.

Active markets to draw the most interest have been Paxton margin of victory propositions and contracts related to candidates drawing endorsement from other GOP political figures like Texas Gov. Greg Abbott. There are a substantial number of contracts related to the total vote turnout in this race as well.

What it covers# of marketsVolume (USD)Open interest (USD)
Paxton/Cornyn margin-of-victory props101,179,817.34684,450.45
Pre-runoff endorsements (Trump, Hunt, Abbott)8321,825.51115,337.34
Runoff total vote count thresholds1361,102.4432,670.42
County-level Paxton runoff wins625,369.599,305.09

While markets have tagged the Cornyn-Paxton runoff as the main event on Tuesday, that contest isn’t the only one to draw interest.

Two US House contests and AG nominee race receiving attention as well

The Democratic US House primary runoffs for districts 18 and 33 have also seen significant trading actvity, as has the GOP primary runoff for the office of Texas attorney general (AG). The combined cumulative volume on contracts related to these races nearly reached $649,000 as of Monday morning.

The Democratic TX-33 primary runoff between Colin Allred and Julie Johnson leads the way on volume of these markets, with trades totaling nearly $329,000 through Monday.

That volume comes from contracts on which candidate will win the nomination and margin of victory propositions on Allred. The GOP AG runoff between Mayes Middleton and Chip Roys has drawn another $239,000 in cumulative volume.

Al Green‘s and Christian Menefee’s Democratic TX-18 runoff had received almost $81,000 in cumulative volume as of Monday as well. While these contracts are focused on Tuesday’s primary runoffs, Kalshi has also opened more than 160 markets pertaining to the November midterm elections.

What it covers# of marketsVolume (USD)Open interest (USD)
TX-33 Democratic primary runoff11329,247.94151,213.94
Texas Attorney General GOP primary runoff2239,146.67126,453.24
TX-18 Democratic primary runoff280,701.6139,334.52

US Senate contract leads Texas November general election volume

The November general election has nearly $7.1 million on contracts. The favored matchup in the US Senate contest between Paxton and Democratic nominee James Talarico has accounted for over $6.4 million of that cumulative volume, and traders are giving Talarico a fighting chance at 46% odds despite Trump’s intervention in the contest.

Talarico is drawing high trading volume as contracts on his win market have seen almost $1.7 million in volume compared to the GOP nominee attracting south of $1.4 million in trades. Over $716,000 has been traded related to the Texas gubernatorial election, US House races, and the Texas lieutenant governor contest.

What is coversMarketsVolume (USD)Open interest (USD)
Texas U.S. Senate general / matchups336,409,697.212,766,643.78
Texas Governor / Lt. Governor / statewide5125,333.2675,202.55
Texas U.S. House / congressional races117475,596.88242,940.01
Texas Attorney General general / Democratic nominee441,661.5420,581.23
Texas redistricting / other politics173,536.8213,607.33

International trading on these events has been comparatively minimal against the volume at Kalshi. Polymarket volume related to Texas political markets has drawn over $18.2 million in cumulative volume*.

  • Texas Republican Senate Primary Winner ($17.0M) — Ken Paxton leads at 95%
  • Texas Senate Republican Primary Runoff Margin of Victory ($112.9K) — Paxton 9%+ leads at 83%
  • Texas Senate Election Winner ($248K) — Republican leads at 56%
  • Texas Senate Election Matchup ($752K) — Talarico & Paxton at 96%
  • Turnout in Texas Senate Republican Primary Runoff ($104K) — 1.2–1.5M turnout leads at 47%
  • Texas Attorney General Republican Primary Runoff Winner ($5.8K) — Mayes Middleton leads at 85%

*Note: Polymarket measures traded value based on actual contract price, rather than Kalshi’s $1 per contract notional volume.

The results of the May 26 primary runoffs will have significant bearing on these November general election markets, which should see an uptick in market volume once candidates are set.

About The Author
Derek Helling
Derek Helling is a journalist who has covered the gaming industry for many publications since 2018. His coverage emphasizes the intersections of gambling with the business of entertainment, the evolution of the legal landscape, technology’s shaping of gaming, and the impact of gambling on society. When he isn’t working on his next story, he enjoys traveling with his wife and spoiling their pair of Munchkin cats.