Iron ore futures in China tumbled as much as 5 percent on Monday, extending losses to a fourth session in a row, as stocks of the steelmaking raw material at the country’s ports rose to the most in more than two years.

Inventory of iron ore at major ports in China, the world’s top importer, hit 111.55 million tonnes as of Dec. 16, the highest since September 2014, according to data tracked by industry consultancy SteelHome.

Spot iron ore prices have surged 87 percent this year, snapping a three-year decline, mainly due to the strength in China’s steel market. The spot benchmark .IO62-CNO=MB touched $83.58 a tonne on Dec. 12, the strongest since October 2014.

But analysts say with steel prices largely spurred by China’s campaign to address excess capacity, iron ore demand could weaken eventually.

“Iron ore prices have remained disconnected to the fundamentals in our view since late October, ranging from $60-$83/tonne despite clearly abundant supply of iron units,” Macquarie analysts said in a note.

“We still believe iron ore supply remains abundant with prices above $60/tonne, and with Chinese mine costs lower in U.S. dollar terms given recent yuan depreciation, we do not see a return of cost inflation in iron ore mining which justifies prices anywhere near current levels.”

The most-traded iron ore on the Dalian Commodity Exchange fell as much as 5.1 percent to 573 yuan ($83) a tonne, and was down 3.7 percent at 581.50 yuan by midday.

Weaker futures could drag spot iron ore back below $80 a tonne if bids consequently drop in the physical market, traders say. Iron ore for delivery to China’s Qingdao port .IO62-CNO=MB was nearly unchanged at $81.49 a tonne on Friday and was also flat for the week, according to Metal Bulletin.

The most-active rebar on the Shanghai Futures Exchange was down 3.2 percent at 3,254 yuan a tonne, also slipping for a fourth consecutive session.

Source: Reuters (Reporting by Manolo Serapio Jr.; Editing by Himani Sarkar)