Copper extended gains to a fourth session on Wednesday as the US dollar eased after its recent blazing rally, while London aluminium held firm after China decided to remove export tax rebates.

Three-month copper on the London Metal Exchange (LME) rose 0.7% to $9,146.5 per metric ton by 0245 GMT, while the most-traded December copper contract on the Shanghai Futures Exchange (SHFE) gained 0.8% to 74,600 yuan ($10,303.44) a ton.

The dollar gave back some of its recent bumper gains, making greenback-priced metals more affordable for other currency holders.

“A weaker dollar has done most of the heavy lifting for base metals. Copper bounced off a crucial technical level last week,” said Kyle Rodda, a senior financial markets analyst at Capital.com.

“Concerns about Chinese demand remain present and will be difficult to shake off, while uncertainty persists about trade-wars and the lack of Chinese stimulus.”

Top base metals consumer China has seen slowing economic growth and government policies so far haven’t managed to uplift investor confidence. LME aluminium climbed 0.5% to $2,657.5 a ton, rising for the second straight session.

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China on Friday said it would cancel the 13% export tax refund for some aluminium and copper products starting Dec. 1.

While China’s copper product exports are considerable, the volume of aluminium exports is significantly higher.

“These measures are likely to support prices on the LME in the long-term as supply in markets outside China is threatening to become scarcer or more expensive,” Commerzbank said.

LME nickel increased 0.6% to $15,955, zinc rose 0.9% to $2,977, lead firmed 0.8% at $2,016 and tin advanced 1% to $29,180.

SHFE aluminium rose 1.3% to 20,740 yuan a ton, nickel added 1.5% to 126,370 yuan, tin firmed 0.3% to 242,860 yuan, lead gained 0.5% at 16,855 yuan and zinc advanced 1.1% at 24,965 yuan.