Skip to main content

To trade in the US, go to polymarket.us

icon for MA-09 House Election Winner
Politics·Nov 4 Elections

MA-09 House Election Winner

icon for MA-09 House Election Winner
Politics·Nov 4 Elections

MA-09 House Election Winner

Polymarket

$23,264 Vol.

Polymarket

$23,264 Vol.

Democratic Party

$8,275 Vol.

95%

Republican Party

$14,989 Vol.

5%

This market will resolve according to the party of the candidate who wins the MA-09 congressional district seat in the U.S. House of Representatives in the 2026 midterm elections. The midterm elections will take place on November 3, 2026. ​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/).Incumbent Democrat Bill Keating secured his party's nomination in the September 1 primary for Massachusetts' 9th congressional district, defeating challenger Craig Swallow and advancing to face Republican R. Tyler MacAllister in the November 3 general election. The district, encompassing Cape Cod, the Islands, and portions of the South Shore and South Coast, has delivered consistent Democratic victories, including a double-digit margin in 2024. Race ratings from multiple forecasters classify the seat as safe or solid Democratic, reflecting its partisan composition and Keating's long incumbency since 2011. Trader consensus at 95.3% for the Democratic nominee aligns with these structural factors and the limited profile of the Republican candidate. A significant late-cycle shift, such as an unforeseen scandal or national political realignment, would be required to alter the outcome.

This market will resolve according to the party of the candidate who wins the MA-09 congressional district seat in the U.S. House of Representatives in the 2026 midterm elections. The midterm elections will take place on November 3, 2026.

​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/).This market will resolve according to the party of the candidate who wins the MA-09 congressional district seat in the U.S. House of Representatives in the 2026 midterm elections. The midterm elections will take place on November 3, 2026. ​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/).
Volume
$23,264
End Date
Nov 3, 2026
Market Opened
Jan 28, 2026, 11:09 AM ET

Resolver

0x2F5e3684c...
This market will resolve according to the party of the candidate who wins the MA-09 congressional district seat in the U.S. House of Representatives in the 2026 midterm elections. The midterm elections will take place on November 3, 2026. ​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/).Incumbent Democrat Bill Keating secured his party's nomination in the September 1 primary for Massachusetts' 9th congressional district, defeating challenger Craig Swallow and advancing to face Republican R. Tyler MacAllister in the November 3 general election. The district, encompassing Cape Cod, the Islands, and portions of the South Shore and South Coast, has delivered consistent Democratic victories, including a double-digit margin in 2024. Race ratings from multiple forecasters classify the seat as safe or solid Democratic, reflecting its partisan composition and Keating's long incumbency since 2011. Trader consensus at 95.3% for the Democratic nominee aligns with these structural factors and the limited profile of the Republican candidate. A significant late-cycle shift, such as an unforeseen scandal or national political realignment, would be required to alter the outcome.

This market will resolve according to the party of the candidate who wins the MA-09 congressional district seat in the U.S. House of Representatives in the 2026 midterm elections. The midterm elections will take place on November 3, 2026.

​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/).This market will resolve according to the party of the candidate who wins the MA-09 congressional district seat in the U.S. House of Representatives in the 2026 midterm elections. The midterm elections will take place on November 3, 2026. ​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/).
Volume
$23,264
End Date
Nov 3, 2026
Market Opened
Jan 28, 2026, 11:09 AM ET

Resolver

0x2F5e3684c...

Related

icon for Will the Democratic Party win the MA-08 House seat?

Will the Democratic Party win the MA-08 House seat?

98%
icon for Will the Republican Party win the PA-09 House seat?

Will the Republican Party win the PA-09 House seat?

96%
icon for Will the Democratic Party win the MA-06 House seat?

Will the Democratic Party win the MA-06 House seat?

97%

Beware of external links.

Frequently Asked Questions

"MA-09 House Election Winner" is a prediction market on Polymarket with 2 possible outcomes where traders buy and sell shares based on what they believe will happen. The current leading outcome is "Democratic Party" at 95%, followed by "Republican Party" at 5%. Prices reflect real-time crowd-sourced probabilities. For example, a share priced at 95¢ implies that the market collectively assigns a 95% chance to that outcome. These odds shift continuously as traders react to new developments and information. Shares in the correct outcome are redeemable for $1 each upon market resolution.

As of today, "MA-09 House Election Winner" has generated $23.3K in total trading volume since the market launched on Jan 28, 2026. This level of trading activity reflects strong engagement from the Polymarket community and helps ensure that the current odds are informed by a deep pool of market participants. You can track live price movements and trade on any outcome directly on this page.

To trade on "MA-09 House Election Winner," browse the 2 available outcomes listed on this page. Each outcome displays a current price representing the market's implied probability. To take a position, select the outcome you believe is most likely, choose "Yes" to trade in favor of it or "No" to trade against it, enter your amount, and click "Trade." If your chosen outcome is correct when the market resolves, your "Yes" shares pay out $1 each. If it's incorrect, they pay out $0. You can also sell your shares at any time before resolution if you want to lock in a profit or cut a loss.

The current frontrunner for "MA-09 House Election Winner" is "Democratic Party" at 95%, meaning the market assigns a 95% chance to that outcome. The next closest outcome is "Republican Party" at 5%. These odds update in real-time as traders buy and sell shares, so they reflect the latest collective view of what's most likely to happen. Check back frequently or bookmark this page to follow how the odds shift as new information emerges.

The resolution rules for "MA-09 House Election Winner" define exactly what needs to happen for each outcome to be declared a winner — including the official data sources used to determine the result. You can review the complete resolution criteria in the "Rules" section on this page above the comments. We recommend reading the rules carefully before trading, as they specify the precise conditions, edge cases, and sources that govern how this market is settled.