Short Answer

Both the model and the market expect Mark Smith to be the SC-01 Republican nominee, with no compelling evidence of mispricing.

1. Market Behavior & Drivers

This prediction market has exhibited a significant downward trend, with the probability of this candidate becoming the Republican nominee falling from a high of 91.5% to a current price of 62.0%. A key event in this decline was a sharp 15.0 percentage point drop on May 29, from 87.0% to 72.0%. While the provided context details events after this date, it does not specify the direct cause for this particular price movement. The price continued to decline following this shift, eventually reaching its current level, reflecting the market's consistent reassessment of the race as it became more competitive.
The overall price action suggests a clear decay in trader confidence. The market initially priced the candidate as a near-certain nominee, but sentiment has shifted to reflect significant uncertainty, which is consistent with the news that the primary is headed to a runoff. The total trading volume of over 24,000 contracts indicates active participation. For example, a volume of 131.0 contracts on June 4 coincided with a continued price fall, suggesting that the downward momentum was backed by market conviction. The initial peak of 91.5% acts as a firm resistance level, while the market is currently testing for support in the low 60s. The current price likely represents the market's updated probability of the candidate winning in a contested runoff scenario.
  • Jenny Costa Honeycutt secured most votes in the initial June 9 primary. Mark Smith holds a significant fundraising advantage over Jenny Honeycutt. Smith has garnered numerous key endorsements from state legislators and the NRA. Prediction markets have consistently favored Smith as the likely nominee. South Carolina primary runoffs consistently experience substantial voter turnout drop-off. Last-minute events may shift momentum before the June 23 runoff.

Who Wins and Why

Outcome Market Model Why
Mark Smith 62.0% 60.9% Mark Smith holds a significant fundraising advantage and has secured numerous key endorsements.
Jenny Costa Honeycutt 47.0% 39.1% Jenny Costa Honeycutt secured the most votes in the initial primary and received significant outside support.

Current Context

South Carolina's 1st Congressional District currently lacks a Republican nominee. As of June 10, 2026, the Republican nominee for South Carolina's 1st Congressional District (SC-01) has not been determined [1][2][3]. The seat is open following incumbent Nancy Mace's decision to run for governor [1][2][3].
A runoff will determine the Republican nominee for SC-01. The Republican primary, held on June 9, 2026, resulted in a runoff election because no candidate achieved the 50 percent threshold [1][2][3]. The runoff between Charleston County Councilwoman Jenny Costa Honeycutt and State Representative Mark Smith is scheduled for June 23, 2026 [1][2][3].
National forecasts predict a close race for US House control. As of June 2026, national election forecasters suggest a tight contest for control of the US House of Representatives [4]. While Republicans maintain a narrow edge in seat ratings, some prediction markets have indicated favorability towards Democratic prospects [4].
Sources (4)
  1. 1SC's 1st Congressional District races headed to runoffs for both...postandcourier.com
  2. 2Graham, Andrews, Clyburn win primaries, but 1st District races go to runoffs - Charleston City Papercharlestoncitypaper.com
  3. 3Who will win race for Nancy Mace’s congressional seat? Here’s who’s in the runoff.islandpacket.com
  4. 4Republicans’ Chances of Losing Control of House: 3 Election Forecasts - Newsweeknewsweek.com

2. Price Chart

Historical Price (Probability)

Outcome probability
Date

3. Significant Price Movements

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

Outcome: Jenny Costa Honeycutt

📉 May 30, 2026: 8.2pp drop

Price decreased from 8.9% to 0.7%

What happened: The provided web research offers no information regarding social media activity, traditional news, or announcements on or around May 30, 2026, that would explain an 8.2 percentage point drop in Jenny Costa Honeycutt's prediction market price for the SC-01 Republican nominee. Later reports confirm Honeycutt finished first in the June 9, 2026, primary election and advanced to the runoff, which contradicts a significant negative price movement before the primary [1][2][3]. Therefore, no primary driver for this market movement can be identified from the available sources, and social media activity appears irrelevant due to a complete lack of relevant findings.

Outcome: Mark Smith

📉 May 29, 2026: 15.0pp drop

Price decreased from 87.0% to 72.0%

What happened: The prediction market price drop for Mark Smith occurred on May 29, 2026, representing a 15.0 percentage point decrease in his likelihood of becoming the SC-01 Republican nominee. However, the available web research details events after this date, specifically the June 9 primary where Smith finished second with about 18% of the vote, leading to a June 23 runoff [1][2][4]. Since the provided information only describes outcomes that post-date the market movement, it is not possible to identify the primary driver for the price drop on May 29, 2026. Therefore, the role of social media in this specific price movement cannot be determined from the available sources.
Sources (4)
  1. 1Crowded primaries for Nancy Mace's seat point to runoffspostandcourier.com
  2. 2Who will win race for Nancy Mace’s congressional seat? Here’s who’s in the runoff.islandpacket.com
  3. 3Jenny Honeycut and Mark Smith move on to runoff for Nancy Mace’s South Carolina seat – Total Newstotalnews.com
  4. 4Mark Smith (South Carolina) - Ballotpediaballotpedia.org

4. Market Data

Contract Snapshot

The market resolves to "Yes" if Jenny Costa Honeycutt wins the Republican nomination for the 2026 SC-01 House seat; otherwise, it resolves to "No." The South Carolina Election Commission will verify the outcome, and the event is mutually exclusive. The market opens on February 6, 2026, at 10:00 AM EST and closes either when Honeycutt wins the nomination or by June 9, 2027, at 10:00 AM EDT, with projected payouts 30 minutes after closing.

Available Contracts

Market options and current pricing

Outcome bucket Yes (price) No (price) Last trade probability
Mark Smith $0.56 $0.88 62%
Jenny Costa Honeycutt $0.60 $0.62 47%

Market Discussion

As of June 10, 2026, the Republican nomination for South Carolina's 1st Congressional District remains undecided following the June 9, 2026, primary election [1][2]. Charleston County Councilwoman Jenny Costa Honeycutt and State Representative Mark Smith advanced to a primary runoff scheduled for June 23, 2026, after no candidate secured the required 50 percent threshold [1][2].

Sources (2)
  1. 1Crowded primaries for Nancy Mace's seat point to runoffspostandcourier.com
  2. 2Who will win race for Nancy Mace’s congressional seat? Here’s who’s in the runoff.islandpacket.com

5. How do Jenny Costa Honeycutt and Mark Smith compare in terms of fundraising and key endorsements heading into the June 23 runoff?

Smith Fundraising$727,000 to $750,700 [1][2]
Honeycutt Fundraising$301,000 to $345,600 [1][2]
Smith Prediction Market FavorOver 70% implied probability [3][4][5][6][7]
Jenny Costa Honeycutt and Mark Smith are competing in a June 23, 2026, Republican runoff after neither candidate secured a majority in the June 9 primary election [8][9]. Honeycutt led the primary with approximately 22.1% of the vote, while Smith followed with 18.0%, securing their spots in the second round [8][9][10][11].
Mark Smith holds a significant fundraising advantage over Honeycutt. Smith has raised between $727,000 and $750,700 throughout the campaign cycle [1][2]. In comparison, Honeycutt's campaign has raised between $301,000 and $345,600 [1][2]. Honeycutt has also benefited from substantial outside support, including a $320,000 ad buy from the Winning for Women PAC [1][2].
Smith has secured numerous key endorsements and leads in prediction markets. He has garnered endorsements from prominent figures, including four state senators, nine state representatives, various sheriffs, and law enforcement officials, as well as the NRA and local community leaders [1][12]. Despite Honeycutt's primary vote lead, prediction markets have consistently favored Mark Smith as the likely Republican nominee, with implied probabilities frequently exceeding 70% before the runoff [3][4][5][6][7].
Sources (12)
  1. 1Lowcountry race: top contenders for SC 1st seat in congress | The Statethestate.com
  2. 2Jenny Honeycut and Mark Smith move on to runoff for Nancy Mace’s South Carolina seat – Total Newstotalnews.com
  3. 3SC-01 Republican nominee? Odds & Predictions 2026kalshi.com
  4. 4SC-01 Republican Primary Winner - Polymarketpolymarket.com
  5. 5SC-01 Republican nominee Elections Prediction Market - Robinhoodrobinhood.com
  6. 6Will Mark Smith Win the SC-01 Republican Primary?lines.com
  7. 7SC-01 Republican nominee? | Prediction Markets | Coinbasecoinbase.com
  8. 8Mark Smith, Jenny Honeycutt advance to runoff in crowded GOP primary for Nancy Mace's House seatthehill.com
  9. 9Crowded primaries for Nancy Mace's seat point to runoffspostandcourier.com
  10. 10South Carolina House District 1 Primary Election Live Results 2026 - NBC Newsnbcnews.com
  11. 11Who will win race for Nancy Mace’s congressional seat? Here’s who’s in the runoff.islandpacket.com
  12. 12Endorsements - Mark Smith for Congressvotemarksmith.com

6. What do the precinct-level results from the June 9 primary reveal about each candidate's geographic strengths and path to victory?

Jenny Costa Honeycutt 1st round voteApproximately 22% [1][2]
Mark Smith 1st round voteApproximately 18% [1][2]
Mark Smith prediction market pricingAround 76% for SC-01 Republican nominee [3]
Detailed precinct-level analysis of the SC-01 Republican primary is currently unavailable. A comprehensive precinct-by-precinct examination of individual candidate geographic strengths and paths to victory for the June 9 primary cannot be completed due to the unavailability of specific precinct data [4][1]. However, Charleston County Councilwoman Jenny Costa Honeycutt and state Representative Mark Smith, both identified as "Lowcountry" candidates, advanced to the runoff election after leading the first round [1][2][5].
Honeycutt and Smith advanced to the June 23 runoff election. On June 9, Jenny Costa Honeycutt secured approximately 22% of the vote, while state Rep. Mark Smith followed with about 18%, with Sam McCown at just under 16% [1][2]. Both Honeycutt and Smith proceeded to the June 23 runoff because no candidate achieved over 50% of the vote [1][2]. The Post and Courier reported that the Associated Press called the runoff for Honeycutt and Smith shortly after polls closed, suggesting a clear consolidation of two candidates with strong support in the Lowcountry areas of the district [1][5].
Mark Smith is currently favored for the SC-01 Republican nomination. According to a prediction market tracker page, the question of the "SC-01 Republican nominee?" priced Mark Smith at approximately 76% at market time. This figure is consistent with his first-round vote advantage being perceived as a favorable position for the runoff and ultimate nomination [3].
Sources (5)
  1. 1Crowded primaries for Nancy Mace's seat point to runoffspostandcourier.com
  2. 2South Carolina's 1st Congressional District election, 2026 - Ballotpediaballotpedia.org
  3. 32026 SC-1 Republican Primary First-Round Winner | Polls & Oddspredictionedge.com
  4. 4South Carolina House District 1 Primary Election Live Results 2026 - NBC Newsnbcnews.com
  5. 5A first look at the Lowcountry congressional race to replace Mace - Statehousecharlestoncitypaper.com

7. Based on historical South Carolina primary runoffs, what is the likely impact of voter turnout drop-off on the June 23 contest between Honeycutt and Smith?

Historical runoff participationBelow 10% of registered voters [1][2]
2024 runoff turnoutApproximately 5.8% [1]
2024 initial primary turnout13.5% [1]
South Carolina primary runoffs consistently experience substantial voter turnout drop-off. The upcoming June 23, 2026, Republican primary runoff for South Carolina's 1st Congressional District is anticipated to see a significant decrease in voter participation [3][4][5][6][1][2]. This forecast is consistent with historical patterns in South Carolina, where primary runoffs frequently record turnout levels below 10% of registered voters [1][2].
Past runoffs illustrate significantly lower participation compared to initial primaries. Specific examples demonstrate this trend, with runoff turnout at 6.3% in 2014 and 9.0% in 2016 [1][2]. More recently, the 2024 South Carolina statewide cycle's runoff saw approximately 5.8% turnout, a notable drop from the 13.5% observed in the initial primary round [1].
Voter engagement in runoffs depends on specific race characteristics. The overall turnout in South Carolina runoffs is highly dependent on factors such as the number and prominence of contested races, alongside the intensity and competitiveness of the particular candidate match-ups [2][7].
Sources (7)
  1. 1June Statewide Primaries and Runoffs a Success: Thanks to Voters, Poll Workers, & Election Officials - SC Votes - South Carolina Election Commissionscvotes.gov
  2. 2SC Runoffs: Nobody Voted - FITSNewsfitsnews.com
  3. 3Mark Smith, Jenny Honeycutt advance to runoff in crowded GOP primary for Nancy Mace's House seatthehill.com
  4. 4South Carolina First Congressional District Primary Election Resultsnytimes.com
  5. 5South Carolina primary results: Several races head to runofflive5news.com
  6. 6SC's 1st Congressional District races headed to runoffs for both...postandcourier.com
  7. 7What to expect in South Carolina's state primary runoffs | South Carolina Public Radiosouthcarolinapublicradio.org

8. Is there any publicly available polling for the SC-01 Republican runoff conducted between the June 9 primary and the June 23 runoff?

Election TypeRepublican Runoff Election [1][2][3]
Runoff DateJune 23, 2026 [1][2][3]
Polling Data StatusNo scientific polling available [1][2][3][4][5]
The SC-01 Republican primary advanced to a runoff. The South Carolina 1st Congressional District Republican primary, held on June 9, 2026, concluded without a definitive nominee, necessitating a runoff election [1][2][3]. This runoff is scheduled for June 23, 2026, and will feature candidates Jenny Costa Honeycutt and Mark Smith [1][2][3].
No scientific polling is publicly available for the runoff. As of June 10, 2026, no publicly available scientific polling data exists for the upcoming June 23, 2026, Republican runoff election [1][2][3]. Leading up to the June 9 primary, only informal straw polls, such as one conducted at an April 2026 GOP forum, were reported [4][5]. No credible, district-wide scientific polling was released for either the primary or the subsequent runoff contest [4][5].
Sources (5)
  1. 1Crowded primaries for Nancy Mace's seat point to runoffspostandcourier.com
  2. 2Who will win race for Nancy Mace’s congressional seat? Here’s who’s in the runoff.islandpacket.com
  3. 3Wrap Up: South Carolina Statewide Primary results & updates - WCIVabcnews4.com
  4. 4South Carolina's 1st Congressional District election, 2026 (June 9...ballotpedia.org
  5. 5Mark Smith leads SC-01 GOP forum straw poll at 34.1%, edging Alex Pelbathabcnews4.com

9. What potential last-minute events, such as a major endorsement or debate performance, could shift momentum before the June 23 runoff?

Window for momentum shiftJune 10 to June 23 [1]
Potential polling bump from endorsementNear "half-dozen point" [2]
Example endorsement dateMay 19 (Trump for Ken Paxton) [3]
Last-minute events significantly influence runoff momentum in final weeks. The period between June 10 and June 23 serves as a natural window for events such as endorsement announcements, campaign consolidation efforts, and final debates or advertisements to shift momentum before a June 23 runoff [1].
Late endorsements often generate measurable closing momentum for candidates. A late endorsement, for example, can create measurable closing momentum for a candidate [3]. President Trump's May 19 endorsement of Ken Paxton in the Texas GOP Senate runoff was described as "just early enough to make a huge positive difference" leading into the runoff [3]. In another South Carolina GOP nomination race, an endorsement from Trump in the final days was projected to produce a near "half-dozen point" polling bump, potentially influencing candidate positioning for an eventual June 23 runoff [2].
Debate performances and final visibility are crucial in runoffs. For general patterns in runoffs, debate performances and last visibility windows are significant [4]. A recap of Georgia's runoff debates highlighted that the debate marathon may be the only time many voters observe candidates face each other directly before the runoff election [4].
Sources (4)
  1. 1Crowded primaries for Nancy Mace's seat point to runoffspostandcourier.com
  2. 2How Trump shaped the closing days of SC’s governor primarypostandcourier.com
  3. 3A Texas-sized endorsement: How President Trump's approval of Paxton over Cornyn impacts Senate GOP runoff - CBS Texascbsnews.com
  4. 4Georgia runoffs: 7 takeaways from political debatesajc.com

10. What Could Change the Odds

Key Catalysts

The Republican primary runoff for South Carolina's 1st Congressional District (SC-01) is scheduled for June 23, 2026, between Jenny Costa Honeycutt and Mark Smith, as no candidate secured a majority in the June 9, 2026 primary election [1][2]. Key catalysts for this election include candidate fundraising and spending, where strong fundraising numbers and effective allocation of funds for voter outreach can signal a candidate's viability and momentum [2]. Endorsements from prominent political figures, particularly those with strong influence among the Republican base such as former President Donald Trump, can significantly impact a candidate's standing [3][4].
Further factors include the candidates' policy positions and campaign messaging on key conservative issues like inflation, affordable housing, border security, and the "America First" agenda, as well as their ability to articulate these positions [2][3]. Voters may also weigh a candidate's prior experience in state government or local council roles [2][3]. Strong performances or missteps in public appearances can shift public opinion and market sentiment [2]. Additionally, the broader national political climate and the performance of the Republican party nationally can affect local races, even in a solidly Republican district like SC-01 [5][4].

Key Dates & Catalysts

  • Expiration: June 09, 2027
  • Closes: June 09, 2027
Sources (5)
  1. 1ballotpedia.org
  2. 2thestate.com
  3. 3southcarolinapublicradio.org
  4. 4pbs.org
  5. 5multistate.us

12. Historical Resolutions

Historical Resolutions: 6 markets in this series

Outcomes: 0 resolved YES, 6 resolved NO

Recent resolutions:

  • KXSC01R-26-MSAN: NO (Jun 10, 2026)
  • KXSC01R-26-SMCC: NO (Jun 10, 2026)
  • KXSC01R-26-LCUN: NO (Jun 10, 2026)
  • KXSC01R-26-JMYE: NO (Jun 10, 2026)
  • KXSC01R-26-JBYA: NO (Jun 10, 2026)