Base metals retreated during Wednesday afternoon trading on the London Metal Exchange (LME), pulled back by copper selling off and diving conclusively into the minus column, traders said.
Copper traded in another wide band - $3,988 down to $3,908 - indicative of nerves becoming frayed ahead of options declaration and the month-end next week.
"It sold off after it failed to break higher, and the others came off as well...It looks like there is natural resistance now between $3,980 and $4,000," one trader said.
Three-months copper ended the kerb at $3,915 a tonne, down from the Tuesday kerb close of $3,945.
"It is just so unpredictable at the moment - the moves are all over the place, and a lot of people are just standing aside," the trader added.
However, others said the market may re-test last week's record high of $4,018 in the near term, although volatile trading is expected to continue ahead of next Wednesday's November option expiry.
"Every time it goes up, the options boys have to cover it and when it goes down, like last week, they have to get out of the cover. They're having a nightmare," another said.
In copper, there are 2,979 calls open at $4,200, and 2782 at $3,800. The November date is currently at $4,100 but open interest is small. When the market eases, delta hedge cover against $4,200 is unwound (sold); when it rises, delta-hedge buying takes place as they get near to being in the money.
Fundamentally, copper was supported by another inventory decline - stocks fell again on Wednesday, registering a drop of 1,975 tonnes to 62,825 tonnes.
Zinc touched a fresh eight-year high of $1,540 at one stage, then fell away, ending at $1,510, down $10, while lead closed at $968, an $11 loss.
Aluminium was unable to drive up to the $2,000 barrier, falling away to close at $1,942, down $22, and back under the $1,950 chart point.
Tin was also lower at $6,100/6,125, versus $6,175/6,200. But nickel rose, correcting slightly after recent losses, and was $75 higher at $11,825. Support is developing around $11,700, traders said.