Base metals had pared their earlier gains by the end of Thursday London Metal Exchange trade, although brokers said the markets should be prepared to face some year-end positioning Friday.
There was little trade across the board although the early advancer was tin, which established a fresh contract high as fund and trade buyers were attracted by supply-side woes.
Declining LME inventories have combined with production problems and concerns over futures supplies to create what a broker described as a "classic and fundamentally driven bull run."
Strike action in Bolivia, a clampdown by Indonesia's government on illegal mining and smelting, as well as limits on future exports from the Asian country have boosted the market and led to an 83% hike in prices this year, culminating earlier Thursday at a peak of $11,800 a metric ton.
Brokers also pointed to a booming electronics sector and new European laws requiring the use of tin solder are also supportive to the market.
Although LME tin had erased some of its earlier gains in the afternoon session, brokers said their near-term money is on the upside with $12,000/ton in the market's sights.
But they also warned that prices could be vulnerable to a profit-taking sell-off by the speculators, estimated to be sitting on around 25% of net long positions.
The rest of the markets were quiet in comparison and generally held recent ranges. Failing to react on the upside to the release of relatively bullish U.S. economic data, the markets drifted sideways and pared early gains.
Although many players are absent for the holiday period, brokers said they plan to "tread carefully" as participants square positions and take profits ahead of the start of the new trading year.
3 months metal (prices in dollars a ton)
Bid – Ask, Change from Wednesday PM kerb
Copper 6379.0-6380.0 Up 4
Lead 1665.0-1667.0 Up 35
Zinc 4245.0-4250.0 Up 40
Aluminium 2830.0-2832.0 Up 10
Nickel 33250.0-33255.0 Dn 250
Tin 11575.0-11600.0 Up 75