Shanghai Futures Exchange copper eased 0.9 percent to 53,150 yuan ($8,054) a tonne on Wednesday buoyed by signs of progress on US tax cuts, but analysts said any reprieve may prove short-lived given weaker oil prices. Shanghai aluminium prices fell 1.7 percent after the Trump administration launched an aggressive new trade action against China on Tuesday, opening the first US government-initiated anti-subsidy and anti-dumping probes in decades into imports of Chinese aluminium alloy sheet. "There's been a little bit of a selldown in the past few days ... the (stronger) dollar, some oil-related drivers," said analyst Daniel Morgan at UBS in Sydney. "In aggregate, I think the base metals have been a bit overbid."