Shares of mining companies Antofagasta (LON:ANTO) and Anglo American (JO:AGLJ) declined Monday as London Metal Exchange (LME) copper prices fell during thin holiday trading.

LME three-month copper prices dropped 1% to $9,854.0 a metric ton. Copper prices have increased in recent weeks amid ongoing uncertainties about U.S. tariffs.

Antofagasta shares decreased 2.1% to 1,893 pence. Despite the daily decline, the stock remains up 3.6% for the week and has gained 34% over the past three months.

Anglo American shares fell 2% to 2,198 pence. The mining company’s stock is still up 2.2% for the week and has risen 22% over the past three months.