LyondellBasell Industries is trading 22.46% higher at $70.35 after-hours, versus the September 30 regular-session close of $57.45; available reporting does not identify a late-breaking catalyst for the sharp rise. - On September 30, Citi downgraded the shares to Neutral from Buy and cut its target to $63 from $72, citing limited upside for polyethylene prices amid weak demand; the downgrade does not explain the after-hours gain. - Broader market performance was mixed.