Asian stocks rallied Monday while oil prices tumbled after the U.S. and Iran agreed to a peace deal aimed at ending nearly four months of conflict , prompting investors to unwind some of the geopolitical risk premium that has dominated markets since February. The strongest reaction was seen in energy markets. U.S. crude oil futures for July delivery were down 4.77% to $80.83 per barrel by 8:27 p.m. ET. Brent futures , the international benchmark, for August delivery traded about 4% lower to $83.