InvestmentsTop Global NewsMarketsReal Estate Oil slumps 4% on concerns over demand and OPEC supply boost By financialnews_rlv83x - August 2, 2021 0 143 Oil prices tumbled about 4 per cent on Monday (Aug 2) as weak economic data from China and the United States, the world’s top oil consumers, and higher crude output from OPEC producers stoked fears of weakness in oil demand and oversupply.