Industrial metals have jumped to a record high on the London Metal Exchange (LME), driven gains in aluminum after the Middle East war disrupted supplies, as well as a recent revival in copper.

The LME Index, which tracks six major metals, has rallied by almost 12% over the past four weeks and was at an all-time peak on the close of April 16. Aluminum has risen about 15% since the start of the Iran war, with around 9% of global output coming from the Middle East.

Aluminum has the biggest weighting on the LME gauge and, together with copper, the two metals make up almost three-quarters of the index.

Banking institution JPMorgan Chase & Co has warned the aluminum industry was heading toward a “black hole” as a serious, prolonged supply deficit is hitting the market after supply losses escalated dramatically in the wake of Iranian strikes directly targeting two key smelters in Abu Dhabi and Bahrain at the end of March. A double blockade of the Strait of Hormuz - by the US and Iran - is also keeping shipments stranded.

While the waterway remains closed, hopes that a ceasefire between the US and Iran will be extended and signs the two sides may be moving closer to a peace deal have aided other metals. They were hit by soaring energy costs and fears of slowing global growth due to the war, but have recovered in recent weeks on signs the conflict might be winding down.

President Donald Trump claimed on April 16, without evidence, that Iran had agreed to terms it has long resisted, including giving up ambitions for a nuclear weapon. Tehran hasn’t confirmed it’s made concessions.

Mercuria Energy Group and BMO Capital Markets forecast this week that copper would surpass a record high hit in January. They cited Chinese buyers coming back to the market and a looming decision on tariffs from the White House that’s encouraging more shipments to the US. Copper has rallied 11% in the last four weeks, and is around 3% off its all-time closing price peak.

The LMEX Metals Index was up 3.6% this week through Thursday. Most metals were down on Friday. Aluminum fell 0.4% to $3,629.50 a ton as of 10:56 a.m. in Shanghai. Copper dipped 0.3%, while nickel rose 2.1%.