Base metals swung lower during late open-outcry trading on the London Metal Exchange (LME) on Monday as short-term sentiment became increasingly uncertain, traders said.
Wide ranges again prevailed, with copper fluctuating either side of the psychological $7,000-a-tonne level throughout the session, eventually ending nearer the lower end of the day's $345 trading band.
"It sold off this afternoon, and stops were hit below the (big) numbers on aluminium and zinc in particular," a trader said. Given the current turbulence in all financial markets, and the sea change in commodity market sentiment, prices are likely to face more downside pressure in the near term as sellers become more confident.
Copper's decline under $7,000 took prices to their lowest since late April, with a low point of $6,880 seen. Final business was just above $7,000 after a late closing flurry on the kerb, but prices still finished $200 a tonne, or 2.8 percent, lower at $7,020.
Analysts said near-term direction would be dictated by financial data from the United States.
"Of the readings that come out this week, by far the most important ones will be the inflation readings," Man Financial analyst Edward Meir said in a report.
"Higher-than-expected numbers could resume the selling in the equity markets and reverberate through to metals...Numbers that are more benign could return most markets - including metals - to a more stable footing."
In the longer term, copper could re-challenge last month's record $8,800 peak, supported by bullish leading indicators from Japan and Europe, some said.
"The underlying economy looks very strong. Leading indicators in Japan and Europe are advancing, although they came off a little in the United States," Barclays Capital analyst Ingrid Sternby told Reuters.
"Copper is facing particular uncertainty and market participants are staying on the side lines, but maybe in the third quarter we could look for higher prices again.
"We could very well go to ($10,000 a tonne) in the medium term," she said.
Prices were supported by news last week that leading producer Grupo Mexico would shut its strike-hit La Caridad copper mine and also threatened to shut down its huge Cananea copper mine.
Mining equities were also mixed, with gains for Xstrata, Anglo American and Antofagasta offset by losses in BHP Billiton and Rio Tinto.
Aluminium, which speared down to $2,462 at one stage, the lowest since early-April, clawed back to $2,500, still down $10 from Friday.
Zinc was also hit hard by liquidation under the $3,300 level, falling to $3,160, the softest since late-May, ending at $3,235, down from $3,320.
Nickel shed 4.5 percent, closing at $19,100, while thinly-traded tin was at $7,900/7,925, against $7,975.
Lead bucked the trend, with prices managing to hold above the $1,000 a tonne level, apart from a brief inconclusive break, closing at $1,105/1,020, up $5.