Short Answer

Both the model and the market expect Jon Bonck to be the TX-38 Republican nominee, with no compelling evidence of mispricing.

1. Executive Verdict

  • Jon Bonck secured a strong 47.7% lead in the March 3 primary.
  • Bonck is endorsed by Donald Trump, Ted Cruz, and Club for Growth.
  • Bonck maintains a significant fundraising advantage over Shelly deZevallos.
  • Shelly deZevallos finished a distant second in the primary.
  • No public polling data exists for the TX-38 runoff election.

Who Wins and Why

Outcome Market Model Why
Jon Bonck 98.6% 97.8% Jon Bonck secured a large lead in the primary, holds major endorsements, and has a significant fundraising advantage.
Shelly DeZevallos 4.5% 2.2% Shelly deZevallos finished a distant second in the primary and faces substantial fundraising and endorsement deficits.

Current Context

Jon Bonck and Shelly deZevallos are competing in the TX-38 Republican runoff. These two candidates advanced to the runoff election for Texas' 38th Congressional District following the March 3, 2026 GOP primary [^][^][^][^]. The Republican nominee will be decided in the runoff election scheduled for May 26, 2026 [^][^][^]. As of May 6, 2026, the final nominee has not yet been determined [^]. In the initial March 3 Republican primary, Jon Bonck received approximately 47.7% of the votes, while Shelly deZevallos garnered between 18.6% and 19% [^][^].
Prediction markets overwhelmingly favor Jon Bonck to win the Republican runoff. The consensus across these markets indicates a strong probability of Bonck securing the TX-38 Republican nomination [^]. Octagon AI reported that the market gives Jon Bonck an approximate 96.9% chance of winning, in contrast to Shelly deZevallos at about 4.5% [^]. Similarly, the Polymarket "TX-38 Republican Primary Winner" market reflects Jon Bonck's likelihood of victory around 95% [^].

2. Market Behavior & Price Dynamics

Historical Price (Probability)

Outcome probability
Date
This prediction market for the TX-38 Republican nominee has exhibited a stable, sideways trend with very high conviction. The price has traded within a narrow range, from a low of 87.0% to a high of 98.6%. The market opened with a high probability of 96.9% and is currently near its peak at 98.6%, indicating consistent and strong sentiment for a 'YES' outcome. A key support level was established at the 87.0% floor, which was briefly touched before a significant price movement. The low total volume of 835 contracts suggests a lack of significant disagreement among traders and a strong consensus.
The most notable event in the chart is a 10.0 percentage point spike on May 2, 2026, when the price jumped from its low of 87.0% back up to 97.0%. However, based on the available information, there was no specific news event, poll release, or other development on that date to explain this sharp recovery. This suggests the dip to 87.0% may have been a brief anomaly or driven by a small number of trades rather than a fundamental shift in market outlook.
Overall, the price action reflects a market with a very high degree of confidence that Jon Bonck will win the runoff election on May 26. The consistently high price, well above 85%, and the low trading volume suggest that traders view this outcome as a near-certainty, with little new information emerging to challenge that belief. The market has effectively priced in a decisive victory for Bonck against Shelly deZevallos.

3. Significant Price Movements

Notable price changes detected in the chart, along with research into what caused each movement.

📈 May 02, 2026: 10.0pp spike

Price increased from 87.0% to 97.0%

Outcome: Jon Bonck

What happened: The provided web research does not identify any specific news, social media activity, or market-related events on May 02, 2026, that would explain Jon Bonck's 10.0 percentage point price spike. While Bonck advanced to a May 26 runoff after the March 3 primary [^][^], no information from the specified date of the spike is available. Therefore, a primary driver cannot be determined from the given sources. Based on the available information, social media activity is irrelevant, as no relevant posts were identified.

4. Market Data

View on Kalshi →

Contract Snapshot

This market resolves to Yes if Jon Bonck wins the Republican Party nomination for the 2026 TX-38 House seat; otherwise, it resolves to No, with the outcome verified by the Democratic and Republican Parties. Trading opens on February 11, 2026, and the market closes after the nomination occurs or by November 3, 2027, with projected payout 30 minutes later. Insider trading by employees of any Source Agencies is prohibited.

Available Contracts

Market options and current pricing

Outcome bucket Yes (price) No (price) Last trade probability
Jon Bonck $0.99 $0.04 99%
Shelly DeZevallos $0.04 $1.00 5%

Market Discussion

The TX-38 Republican nomination advanced to a May 26 runoff between Jon Bonck (approx. 47% of the vote) and Shelly deZevallos (approx. 19%), as neither candidate secured over 50% in the March 3 primary [^][^]. Jon Bonck, notably backed by former President Trump, is widely favored in prediction markets, where his odds of winning have been as high as 83-95% [^][^][^].

5. What evidence underpins Jon Bonck's position as the dominant favorite in the TX-38 Republican runoff?

Runoff Win Probability93% to 97% (May 26 runoff) [^][^]
Primary Vote Share47.7% (March 3, 2026 primary) [^][^]
Funds RaisedOver $1 million [^][^]
Jon Bonck is the overwhelming favorite in the TX-38 Republican runoff. Prediction markets widely indicate a high probability of his victory in the May 26 runoff, estimating his chances between 93% and 97% [^][^]. Specific market projections further underscore this confidence, with Octagon placing his odds at 96.9%, and both Solflare and Defirate assigning a 95% likelihood [^][^].
Bonck's strong primary performance and campaign resources bolster his position. He secured 47.7% of the vote against ten candidates in the March 3, 2026, TX-38 GOP primary [^][^]. His candidacy is further strengthened by a significant Trump endorsement and a substantial fundraising effort, having accumulated over $1 million [^][^]. The TX-38 district itself, established in 2022 in the Houston suburbs, is considered a reliably Republican seat, with the incumbent Wesley Hunt having pursued a Senate bid [^][^].

6. How do Jon Bonck's and Shelly DeZevallos's fundraising and campaign spending compare for the May 2026 runoff?

Jon Bonck Fundraising Advantage$310,838 (as of February 11, 2026) [^]
Jon Bonck Spending Advantage$257,390 (as of February 11, 2026) [^]
Jon Bonck Total Receipts$1,476,325.09 (April 1, 2025 to March 31, 2026) [^]
Jon Bonck held a significant financial lead over Shelly deZevallos as of February 11, 2026 [^] . Bonck's fundraising receipts totaled $1,075,937, which was $310,838 (approximately 41%) more than deZevallos's receipts of $765,099. His spending amounted to $679,301, reflecting a $257,390 advantage (about 61% greater) over deZevallos's disbursements of $421,911 [^].
Bonck's financial activity continued through March 2026, lacking comparable deZevallos data. For the more recent period spanning April 1, 2025, to March 31, 2026, Jon Bonck's total receipts reached $1,476,325.09, with total disbursements of $1,037,936.55 [^]. The available research does not provide comparable financial summary figures for Shelly deZevallos for any period beyond February 11, 2026 [^]. Both candidates advanced from the March 3 Republican primary and are scheduled to compete in the runoff election on May 26, 2026 [^][^].

7. What potential catalysts before the May 26 runoff could improve Shelly DeZevallos's chances against Jon Bonck?

DeZevallos FundraisingOver $666,000 [^][^]
Bonck FundraisingOver $1M [^][^]
DeZevallos Market OddsLow-single-digit odds [^][^][^]
DeZevallos's chances could improve through endorsements and funding. Potential catalysts before the May 26 runoff include successfully consolidating additional local and influential Republican endorsements and networks [^]. Her campaign currently lists endorsements from Texas and national Republican figures, which could translate into late voter and donor transfers if more leaders join or if existing endorsers become more visible during the runoff period [^]. A late fundraising or operational surge is another realistic catalyst [^][^]. Pre-runoff reporting indicated DeZevallos had raised over $666,000, while Bonck had raised over $1 million [^][^]. Narrowing this spending and resources gap could benefit DeZevallos among persuadable and turnout-critical segments [^][^].
Negative developments for Bonck could significantly alter DeZevallos's odds. Current market consensus assigns DeZevallos low-single-digit odds relative to Jon Bonck [^][^][^]. Absent major shocks, the most direct catalysts to improve DeZevallos's chances would be any late negative news or credibility-impacting events affecting Bonck [^][^][^]. Such events, combined with credible performance or positioning from DeZevallos, could instigate a rapid shift in endorsement, donor, or voter coalitions [^][^][^]. Prediction market pages for the TX-38 Republican nominee indicate that trading remains open, allowing odds to shift as new developments emerge before the May 26 resolution [^][^].

8. Is any public polling data available for the TX-38 Republican runoff for the period between the March 3 primary and the May 26 election?

Jon Bonck Pre-Primary Poll22% (February 3-10, 2026) [^]
Shelly deZevallos Pre-Primary Poll10% (February 3-10, 2026) [^]
Jon Bonck Primary Vote46.8%-47.7% [^]
No public polling data exists for the TX-38 Republican runoff. The available research does not contain public polling data specifically for the Texas 38th Congressional District Republican runoff election for the period between the March 3 primary and the May 26 election. The only polling information available is a pre-primary poll conducted by the University of Houston's Hobby School of Public Affairs. This survey, conducted between February 3-10, 2026, prior to the primary election, showed Jon Bonck leading with 22% and Shelly deZevallos with 10%, with 50% of voters undecided [^].
Primary election results show Bonck and deZevallos advancing. In the primary election held on March 3, Jon Bonck garnered between 46.8% and 47.7% of the vote, while Shelly deZevallos received between 18.6% and 18.8% [^]. The runoff election between these two candidates is scheduled for May 26, 2026 [^].

9. Which key political figures and organizations have endorsed Jon Bonck versus Shelly DeZevallos ahead of the May runoff?

Jon Bonck - Trump EndorsementFebruary 16, 2026 [^][^][^]
Jon Bonck - Other EndorsementsU.S. Senator Ted Cruz [^][^] and Club for Growth PAC [^][^]
Shelly DeZevallos EndorsementCClub for District 38 [^]
Jon Bonck has garnered significant endorsements from prominent national political figures. Former President Donald Trump publicly endorsed Bonck on February 16, 2026 [^][^][^]. Additionally, U.S. Senator Ted Cruz has publicly endorsed Bonck [^][^].
Bonck also received key organizational backing, while DeZevallos secured local support. The Club for Growth PAC endorsed Bonck, highlighting his commitment to fiscal conservatism [^][^]. In contrast, Shelly DeZevallos received an endorsement from CClub, a local organization, for District 38 as part of their 2026 Republican Runoff Endorsements [^].

10. What Could Change the Odds

Key Catalysts

Initial expectations for the TX-38 Republican primary winner heavily favored Jon Bonck, with Polymarket showing him as the leading outcome at 83% on 2025-10-30 and later at ~94.7% on 2026-02-06. Octagon AI reported ~96.9% at a later date [^][^]. These strong implied probabilities were cited as being driven by fundraising and endorsements, suggesting that updates concerning these factors would function as key re-pricing events in prediction markets [^].
The March 3, 2026, Republican primary results saw Jon Bonck lead with 47.7% of the vote and Shelly deZevallos receive 18.6%, advancing both to the May 26, 2026, Republican primary runoff [^] [^] . A major catalyst for prediction markets is any late swing in support that changes whether a candidate clears the 50% threshold needed to avoid a runoff, as per Texas primary rules [^][^]. Such a shift would lead to particularly volatile pricing around whether the winner is decided in the initial primary round or proceeds to the May 26 runoff qualification [^][^].

Key Dates & Catalysts

  • Expiration: November 03, 2027
  • Closes: November 03, 2027

11. Decision-Flipping Events

  • Trigger: Initial expectations for the TX-38 Republican primary winner heavily favored Jon Bonck, with Polymarket showing him as the leading outcome at 83% on 2025-10-30 and later at ~94.7% on 2026-02-06.
  • Trigger: Octagon AI reported ~96.9% at a later date [^] [^] .
  • Trigger: These strong implied probabilities were cited as being driven by fundraising and endorsements, suggesting that updates concerning these factors would function as key re-pricing events in prediction markets [^] .
  • Trigger: The March 3, 2026, Republican primary results saw Jon Bonck lead with 47.7% of the vote and Shelly deZevallos receive 18.6%, advancing both to the May 26, 2026, Republican primary runoff [^] [^] .

13. Historical Resolutions

Historical Resolutions: 20 markets in this series

Outcomes: 4 resolved YES, 16 resolved NO

Recent resolutions:

  • KXTXPRIMARY-37R26-JMAL: NO (Apr 20, 2026)
  • KXTXPRIMARY-38D26-TCOU: NO (Mar 06, 2026)
  • KXTXPRIMARY-38D26-MMCD: YES (Mar 06, 2026)
  • KXTXPRIMARY-38D26-MHUN: NO (Mar 06, 2026)
  • KXTXPRIMARY-38R26-MPRA: NO (Apr 20, 2026)