Mumbai: India Ratings and Research have revised its outlook on the base metals sector, zinc, aluminium, copper and coal to ‘negative’ from ‘stable’ for FY21as the coronavirus outbreak and subdued global demand is keeping the prices low. "The prices may gradually improve as the epidemic is contained and the second phase of US-China trade negotiations is concluded,” said Ind-Ra analyst Siddharth Rego in a recent report. The agency expects aluminium prices to experience downward pressure due to weak end-user demand and surplus market supply.