Sarah Trone Garriott leads the IA-03 House race in trader consensus due to the district's history of narrow margins, her edge in recent fundraising, and the typical midterm dynamics favoring the opposition party in competitive seats. Incumbent Zach Nunn won by under two points in both 2022 and 2024, with the seat rated a toss-up or lean Democratic by multiple forecasters entering the cycle. Trone Garriott, an Iowa state senator, secured the Democratic nomination unopposed in June and has highlighted differences on health care access and abortion policy. Nunn remains positioned through his incumbency and focus on tax and security issues, though no major late developments have shifted the race's fundamentals ahead of the November general election.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedIA-03 House Election Winner
Sarah Trone Garriott (D)
74%
Zach Nunn (R)
25%
Sarah Trone Garriott (D)
74%
Zach Nunn (R)
25%
A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time all of the 2026 House elections are conclusively called by this market's resolution sources. A candidate without a ballot-listed affiliation to either the Democrat or Republican parties will be considered a member of one of these parties based on the party with which they most recently expressed their intent to caucus at the time all of the House elections are conclusively called by this market's resolution sources.
This market will resolve based on the result of the election as indicated by a consensus of credible reporting. If there is ambiguity, this market will resolve based solely on the official results as reported by the United States government, specifically the Federal Election Commission (https://www.fec.gov/).
Market Opened: Dec 16, 2025, 11:59 AM ET
Resolver
0x2F5e3684c...A candidate's party will be determined by their ballot-listed or otherwise identifiable affiliation with that party at the time all of the 2026 House elections are conclusively called by this market's resolution sources. A candidate without a ballot-listed affiliation to either the Democrat or Republican parties will be considered a member of one of these parties based on the party with which they most recently expressed their intent to caucus at the time all of the House elections are conclusively called by this market's resolution sources.
This market will resolve based on the result of the election as indicated by a consensus of credible reporting. If there is ambiguity, this market will resolve based solely on the official results as reported by the United States government, specifically the Federal Election Commission (https://www.fec.gov/).
Resolver
0x2F5e3684c...Sarah Trone Garriott leads the IA-03 House race in trader consensus due to the district's history of narrow margins, her edge in recent fundraising, and the typical midterm dynamics favoring the opposition party in competitive seats. Incumbent Zach Nunn won by under two points in both 2022 and 2024, with the seat rated a toss-up or lean Democratic by multiple forecasters entering the cycle. Trone Garriott, an Iowa state senator, secured the Democratic nomination unopposed in June and has highlighted differences on health care access and abortion policy. Nunn remains positioned through his incumbency and focus on tax and security issues, though no major late developments have shifted the race's fundamentals ahead of the November general election.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated



Beware of external links.
Beware of external links.
Frequently Asked Questions