This market resolves YES if either the Republican Party or the Democratic Party splits into two or more separate political parties that each field their own candidates in federal elections (House, Senate, or presidential). A split requires the creation of a new party organization with distinct ballot access and independent candidate recruitment, not merely internal factions or primary contests. The market resolves NO if both parties remain intact through the end of 2028, regardless of internal divisions or contested primaries.

Sources for resolution: Federal Election Commission candidate filings, state election board records, and major news outlets covering party formation announcements.