Temporary funding expiration coupled with midterm elections, 43% probability of a U.S. government shutdown

According to monitoring by PolyBeats, on October 29 Beijing time, the prediction market Polymarket launched "Will the U.S. federal government shut down within the year," with the current "Yes" probability at 42.5%.

On September 2, Trump signed the "Continuing Appropriations and Extensions Act of 2027," extending temporary funding until December 11; if it expires, a funding gap could begin on December 12. Before the pre-election recess, the House passed only three of the twelve appropriations bills, and the Senate has not passed corresponding versions, making it nearly impossible to complete the regular bill-by-bill process; the only options are to bet on a year-end omnibus, sign another short-term continuing resolution, or a mix of both.

During the lame-duck period after the midterm elections, the two parties will fight not only over spending figures: defense and non-defense levels, homeland security and the border, disaster and wildfire relief, nutrition programs, housing and infrastructure will all come into play. Reports by The Hill and others describe Trump's position in funding negotiations after the midterms as an uncertain variable; if Republicans lose in the elections, the lame-duck bargaining chips will be repriced.

The most recent nationwide full-government shutdown occurred from October 1 to November 12, 2025, lasting about 43 days. At that time, the start of fiscal year 2026 had neither regular appropriations nor temporary funding; the Republican-led short-term funding bill did not include an extension of the Affordable Care Act's enhanced premium tax credits, and Senate Democrats blocked it multiple times, resulting in a stalemate lasting more than a month.