Copper ended a week of almost uninterrupted gains on the London Metal Exchange (LME) firmly esconced at record levels above $3,900, amid continued fund buying sparked by supply worries and falling stocks.
"It has been one-way traffic for the last few days, and today was no different. This is a market that no one will sell short because there is just no downside," a trader said.
Three-months hit a new all-time peak of $3,918 a tonne before ending the kerb at $3,915, up $32 from Thursday's kerb close. Last Friday, copper stood at $3,770.
"The mood is now looking beyond $3,900 to a challenge of $4,000 as the drop in LME stocks has really boosted the bulls, apart from the other supply disruptions," a trader said.
Supply breakdowns in North America and Africa and falling LME stocks have kept the market under pressure.
In the United States, Asarco has closed its Hayden smelter in Arizona for repairs, with the company already gripped by a 3-1/2-month strike, reducing output by around 20 percent.
Canada's Falconbridge announced on Thursday it had resumed output of copper concentrate at its strike-ridden Kidd Creek facility in Ontario using non-unionised workers, after earlier declaring force majeure on a number of contracts.
In Zambia several plants have cut production or closed and more are threatened by energy shortages, while the government has scrapped import duty on fuel in an attempt to keep the mining sector running.
And LME stocks fell 1,025 tonnes to 70,475 on Friday - down more than 15 percent from 11-month highs of 84,300 in late September.
"The majority of people think copper is far too high, but you cannot short it," a fund source said.
"That has been tried and failed since $3,500...the systems funds are all long. What we're seeing is residual buying, it is still dragging money in."
Zinc was also strong, hitting a new eight-year high of $1,490 a tonne before last trade at $1,479, up $20. The market was boosted by falling stocks, as LME inventories fell 3,000 tonnes to 517,275 tonnes, the lowest for 3-1/2 years.
Aluminium cleared stubborn resistance at $1,900, closing at $1,907, up $18, around the highest since last-September. Nearby tightness increased, with cash/October at $15 backwardation. Nickel was pressured by negative charts, as prices neared a test of $13,000. Last trade was at $13,100, down $100. Tin was at $6,590/6,600, up $40, while lead rose $9 to $969.