Condition: Republicans win a majority of seats in the U.S. House of Representatives in the November 3, 2026 elections (at least 218 seats won by Republican Party candidates, counting delegations as certified; independents count for neither party). If Democrats or no party win a majority, this market resolves N/A.

Resolves YES if the S&P 500 index's official closing level on its last trading day of 2027 is higher than its official closing level on November 3, 2026 (Election Day). Resolves NO if it is equal or lower. Uses S&P Dow Jones Indices' published closes.

This is one half of a conditional pair; its twin asks the same question if Democrats win the House. Comparing the two shows what the market thinks control of the House changes.

Starting probability is a seed, not a forecast: anchored on public prediction-market prices where a related market exists, otherwise a prior.