If exactly 4 members of the Senate Republicans lose re-election in 2026, then the market resolves to Yes. Members count as losing re-election if they actively seek re-election (by filing candidacy or appearing on ballot) but fail to win. This includes losses in primaries, general elections, runoffs, retention elections, or recalls. Members who retire, withdraw before primaries, die, resign, or are disqualified do not count as losses. If redistricting forces two group members against each other, the loser counts. Members who switch parties after issuance remain part of the original group. If a member loses their party primary but wins as an independent, they did not lose re-election. This market will close and expire early if all relevant elections are completed and certified.