Incumbent Mike Thompson leads trader pricing in the CA-04 contest after securing 41% in the June 2 top-two primary and advancing alongside challenger Eric Jones, who finished second at 22%. Thompson’s long tenure, committee role on Ways and Means, and broad Democratic endorsements have sustained his edge in a district redrawn under Proposition 50 to include more rural northern counties. Jones, a younger former venture capitalist, has emphasized generational change, affordability, and progressive priorities while self-funding heavily, yet trails in name recognition and establishment support. With the November 3 general election featuring an all-Democratic matchup in a seat rated solidly Democratic by forecasters, traders assign Thompson the clearest path to victory while pricing residual uncertainty around turnout and the altered electorate. No major developments have shifted positioning since the primary.