President Donald Trump is still considering a U.S. diesel export ban, but prediction markets put the chance of a broad prohibition this month at relatively low levels. Polymarket assigns an 11% probability to an announcement by Oct. 31, with more than $181,000 traded, while Kalshi traders give a ban before Election Day a 17% chance. Trump said Wednesday that his administration discusses the measure "every day," acknowledging that it could reduce diesel prices while raising gasoline costs. Energy Secretary Chris Wright opposes a blanket ban, warning it could reduce refinery efficiency and increase gasoline and jet fuel prices. The administration has also discussed voluntary export limits with refiners and urged France and Germany to release emergency diesel reserves. Goldman Sachs Group Inc. estimates a ban could initially lower U.S. diesel prices by about 25 cents per gallon each week, or roughly 4%, before storage constraints force refiners to reduce crude processing and potentially raise gasoline prices by about 30 cents per gallon. Jefferies downgraded Valero Energy Corp. and Marathon Petroleum Corp. to Hold on Sept. 22, citing a possible ban as a major refining-industry risk.