Copper is now changing hands for less than US$7,000 per tonne with the LME official cash price on Thursday at $6,838/t.

In the first four trading days of the week, the red metal lost 3.2% of its value. The last time it saw such a drop was back in early December.

While the base metal was affected by a global sell off in equities this week - seemingly linked to rising US bond yields on Monday and, subsequently, trading in exchange traded notes that allow investors to bet on low volatility - LME copper warehouse stocks have also risen 75% over the past three weeks.

With 62% Fe iron ore prices also slightly off on Thursday, it was hardly surprising to see BHP (AU:BHP) and Rio Tinto's (LN:RIO) stocks off 1.3% and 3.2%, respectively.

Most analysts were expecting this bearish tone to be short lived, with several large copper mines in South America set to enter crucial wage negotiations over the next few months. The expectation is these talks will lead to strike action as workers push for higher wages and increased benefits following a stronger run in the copper price recently.

Gold, meanwhile, regained some ground overnight. It sunk as low as $1,307 per ounce at around midday on Thursday in the UK, but was back above $1,320/oz at 7am on Friday. Just a week ago, it was closer to $1,350/oz.