(Bloomberg) -- Commodities from coal to aluminum posted huge swings in London on Thursday, as traders said prices were reacting to speculation that China’s leadership is growing concerned over recent sharp declines in prices.

Aluminum, one of the most energy-intensive metals, bounced back 2.3% on the London Metal Exchange to reverse earlier losses that followed yesterday’s two-month low. Copper, nickel, lead and zinc also erased early losses.

Bloomberg couldn’t verify the speculation, widely circulated on Chinese social media, that a Chinese leader is growing concerned that the correction in raw material prices will lead to unnecessary turbulence in the economy. The State Council didn’t respond to calls for comment.

In frenzied moves after China’s midday trading break, coal futures erased an almost 10% decline before tumbling again to the lower daily trading limit. The most-active thermal coal contract on the Zhengzhou Commodity Exchange closed 8.1% lower on Thursday. Futures had started the morning falling by their daily limit on news of a cap on prices, before almost erasing all their losses in the afternoon and then swiftly plunging again.

Base metals were also boosted by a plunging dollar after the U.S. posted its weakest growth of the pandemic recovery period on supply woes and a surge in Covid-19 cases. GDP expanded at a 2% annualized rate in the third quarter following a 6.7% pace in the second quarter, well below market expectations. The Bloomberg Dollar Spot Index fell to its lowest in more than a month on the assumption that there is now less pressure on the Federal Reserve to act on rising inflation.

Aluminum on the LME settled at $2,746.50 a metric ton as of 5:54 p.m. local time, while copper gained 1.2% and nickel settled 0.8% higher.

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