Union Pacific is trading 5.9% up at $290.00, with no company-specific announcement or reliable report explaining the after-hours jump. - It closed at $273.77 on September 25, 2026. - On September 22, regulators said they would continue reviewing the Union Pacific–Norfolk Southern merger application; this is not a confirmed explanation for the move. - Broader market sentiment was positive, but available evidence does not establish it caused the sharp after-hours rise.