China’s iron ore imports jumped to a record last month, a sign that overseas miners are winning a greater share of the market in the world’s biggest consumer. Steel exports soared as the nation sells its glut overseas.

A gauge of returns on raw materials tumbled to the lowest since at least 1991, extending the agony that producers of energy, industrial metals and agricultural commodities faced in 2015.

After oil sank into the $20s this week, will iron ore follow suit?

Wheat prices jumped in trading Tuesday, striking a rare bullish note amid a generally gloomy outlook for commodities, after a U.S. government report showed a potential smaller-than-expected winter crop.

Japan’s trading companies fell after Sumitomo Corp. withdrew its full-year earnings forecasts because of a 77 billion yen ($654 million) charge on its Ambatovy nickel project in Madagascar, following a collapse in the price of the metal.

Oil dropped below $30 a barrel in New York for the first time in 12 years on concern that turmoil in China’s markets will curb fuel demand.