SINGAPORE – Iron-ore cargoes from Australia’s Port Hedland, the world’s biggest bulk export terminal, jumped to an all-time high of almost half a billion metric tons last year, offering fresh evidence of burgeoning global supply at a time when bearish forecasts for the commodity are stacking up.

Exports from the port, which handles material for BHP Billiton, Fortescue Metals Group and Roy Hill Holdings, climbed 5% to 46.1-million tons in December to set a monthly record, according to Pilbara Ports Authority figures on Tuesday. For all of last year, shipments were 497-million tons, up from 479-million in 2016, according to Bloomberg calculations.

While iron ore rallied into a bull market last month amid speculation demand will remain robust, especially after China eases steel output curbs imposed this winter, there’s been a flurry of forecasts that gains aren’t sustainable. On Monday, the Australian government warned prices will drop through to 2019, falling back below $50 a ton, as the country’s miners and those in Brazil churn out an additional 100-million tons. In December, Goldman Sachs Group Inc. said the commodity will retreat on prospects for rising mine supplies.

“Iron ore’s latest advance indicates expectations for a springtime recovery in steel production,” Everbright Futures Co. said in a note, referring to the expected demand revival when the curbs end. “Even though port inventories in China are very high, prices can probably be sustained for a while.”

SGX AsiaClear futures traded 0.7% higher at $76.42 a ton at 1:02 p.m. in Singapore, heading for the highest close since September 5 amid a four-day advance. The commodity closed out 2017 on a strong note, gaining 6.2% in December following a 17% surge in November.

Port Hedland is the main gateway to Australia’s Pilbara, center of the nation’s mammoth iron-ore industry, the world’s largest. Roy Hill is seeking to boost annual exports to 60-million tons from 55-million, The Australian newspaper reported on Tuesday, citing documents submitted to the state government.

Cargoes from Port Hedland to China were a record 39.1-million tons last month, compared with 37.4-million a year earlier, according to the authority. That’s helped to boost port stockpiles in China to unprecedented levels of more than 150-million tons, according to Shanghai Steelhome E-Commerce Co.

In its resources outlook, the Australian government said free-on-board prices will average $52.60 this year and $48.80 in 2019. Exports from the top shipper and Brazil will increase to 1.32-billion tons next year from 1.22-billion in 2017, the Department of Industry, Innovation and Science estimates.