US President Donald Trump's promise of a $5,000 cash payout to all adult citizens if Republicans retain control of Congress is adding fresh uncertainty to the Treasury market ahead of a 30-year bond auction. The pledge, made during the Republican Midterm Convention in Dallas, renews concerns about Washington's fiscal discipline and erratic policymaking. Treasury yields fluctuated in a narrow range following the announcement, though the proposal lacks details and is considered unlikely to become law. The move comes as investors already grapple with fiscal trajectory worries, complicating the outlook for government debt supply and demand dynamics.