Shares of Australian iron ore miners surged the most in over two years on Tuesday after the country’s top trading partner China’s pledge for more policy stimulus to spur economic growth raised the prospects for its property sector.

The mining index advanced as much as 4.1% in its best intraday jump since mid-November 2022.

It was 3.2% higher at 0400 GMT, versus a dip in the benchmark ASX200 index.

Shares of Rio Tinto, the world’s biggest iron ore producer, advanced as much as 5.5% in their biggest intraday gain since mid-November 2022. They were last 4.2% higher.

BHP Group, the world’s largest listed miner, rose 3.2%, set for its best day since late September, while No.4 producer Fortescue jumped 6% to a near two-month high.

The rush comes after months of sell-offs in miners of iron ore, used to make steel, as prices remained under pressure due to subdued demand from China’s debt-ridden property sector, a key customer of steel.

China is Australia’s biggest trading partner and buys around 80% of its iron ore, the country’s largest export.

Now, China’s first shift in policy stance in 14 years has revived optimism in Australian miners.

Beijing will adopt an “appropriately loose” monetary policy alongside a more proactive fiscal policy next year to spur growth, the Politburo was quoted as saying on Monday.

Australian shares edge higher on commodity boost; RBA flags persistent inflation

“To the extent that the Chinese government increases monetary and fiscal stimulus this is bullish in the short term for Australian miners who produce iron ore, copper, metallurgical coal and other commodities,” said Jon Mills, a mining equity analyst at Morningstar.

But “we are sceptical that it will be enough to overcome what we see as long-term structural headwinds within the country.”

Miners have lost around 13% this year and are heading for their worst year since 2015, making them the worst-performing sector in Australia this year.