The Globe and Mail reports in its Wednesday, May 27, edition that Aluminum prices reached a four-year high on Tuesday, driven by rising alumina costs and concerns over supply shortages from Gulf producers. A Reuters dispatch to The Globe reports that three-month aluminum on the London Metal Exchange rose 0.8 per cent to $3,680, after hitting $3,707.50, its highest since March, 2022 (all figures U.S.). The all-time peak of $4,073.5 was recorded on March 7, 2022, amid Russia's unprovoked invasion of Ukraine. Aluminum support came from a 5-per-cent rise in September alumina futures on the Shanghai Futures Exchange, reaching their highest since May due to concerns about bauxite supply from Guinea. Guinea, the world's leading bauxite producer, is mulling export quotas for mining companies due to rising shipping costs that are impacting revenue. The new policy is expected to be finalized in June. The Middle East conflict has triggered the largest aluminum supply shock in at least 50 years, analysts at Citi said in a note last week, accelerating inventory drawdowns of around three million tonnes this year from already historically low levels and prompting strong futures buying.