Copper prices, which hit four-month highs at midday on the London Metal Exchange (LME), reversed direction in Monday afternoon trade to end lower.
Traders said the decline was triggered by overhead technical resistance stalling the earlier advance, as well as a contraction in the cash/threes backwardation from midsession levels of $100.
"It was looking overbought up there (the highs), and the backwardation (contracting) also whipped it around," one trader said.
The cash/threes backwardation was indicated at $68/73 at the close, while final three months trade was at $2,830 a tonne, down $23 from Friday's kerb close.
"It is a poor close - we were looking for it to stay above $2,860 - and that is unlikely to get the funds excited," a fund source said.
Major funds were more focused on energy, where prices are booming, and bond markets, where US rate perceptions are the driver, he said. Earlier, prices drove up to a peak of $2,885/2,890 on short covering CTA and industry buying, which triggered buy-stops through $2,865.
But levels around $2,890 proved difficult to erode, and the market may need to retrace further before trying to challenge $2,900, traders said.
Other metals were mixed, although tin was firmer after a breach of $9,000 triggered covering and buy-stops. It concluded at $9,175, up $375 from Friday and a two-month high.
Nickel rose $200 to $13,550/565, but was quiet, while aluminium gained just $1 at $1,729.
Lead and zinc were unchanged at $870 and $1,002 respectively.