At the end of the latest offshore session, benchmark iron ore for immediate delivery to the port of Tianjin in China was trading at $US55.00 a tonne, up 0.9 per cent from a six-year low of $US54.50 a tonne.

Over the last month the commodity has given up about 15 per cent of its value, the latest sign of turbulence after a horror 2014 that saw its price cut in half.

The commodity lost 5 per cent last week alone as several forecasters downgraded their projections and local miner Fortescue Metals Group abandoned a $US2.5 billion ($A3.2bn) debt refinancing.

Among analysts trimming expectations were UBS and HSBC, while the federal government’s Department of Industry and Science said it now expects an average price of $US60 for 2015. That compares unfavourably to its prior expectation of $US63, declared in a December report.

Less optimistic is rich lister Chris Ellison, who told Fairfax that his mining services firm, Mineral Resources, is banking on a price below $US50 a tonne in the medium-term.

“We want to make money when iron ore is sub-$US50 a tonne and we want our clients to as well,” Mr Ellison said.

“Everyone assumes it (the price) will go down to what the lowest-cost producer’s costs will be. That’s never been the case in history. It is just until the surplus supply comes out of the market; whatever it takes to shake them out. But it will keep sinking until that oversupply disappears.”

Indeed, the oversupply shows no sign of fading in the near-term, with West Australian Premier Colin Barnett ramping up the pressure on mining heavyweights Rio Tinto, BHP Billiton and Vale to curb their production expansion plans.

“This has been one of the dumbest corporate plays I think I’ve ever seen,” he said last week.

“The two big ones in Western Australia and the Brazilians have been putting too much iron ore into the market and they’ve precipitated a continuing downward trend in iron ore prices.”

Rio, BHP and Vale still maintain healthy margins given operating costs that have fallen below $US20 a tonne, but those margins are sharply below where they where at the start of 2014 as the iron ore price sat above $US135 a tonne.