NextFin News -- Major indexes in Japan and South Korea on Monday tumbled more than 5%, as investors sold off risk assets amid the U.S. and Iran trading threats as the conflict in the Middle East has entered its fourth week.   Brent crude on rose 0.65% to $112.68 per barrel while the U.S. West Texas Intermediate was up 0.8% at $99 per barrel. Goldman Sachs has significantly revised its forecasts, expecting Brent to average $110 in March-April, up from $98 previously, and WTI to average $98 in March and $105 in April. “We now assume that Hormuz flows remain at only 5% of normal levels for a longer 6-week period before a gradual 1-month recovery,” Goldman Sachs said, adding that prices are likely to trend higher over that period until investors gain confidence that a prolonged disruption can be ruled out. Gold prices fell 6.6% to $4,188.99 an ounce,  a nearly four-month low. Expectations that war-driven inflation will keep interest rates elevated weighed on the non-yielding metal’s appeal relative to interest-bearing assets. Meanwhile, silver prices sank by around 8% to $62.39.U.S. and Iran Trade ThreatsU.S. President Donald Trump said on Saturday that he would “obliterate” Iran’s power plants if Tehran failed to fully reopen the Strait of Hormuz, a choke point for global energy flows, within 48 hours. Iran pushed back, threatening to target U.S. banks, energy infrastructure and drinking water facilities in the Gulf if the U.S. carries out its ultimatum. Iran’s Parliament speaker Mohammad Bagher Ghalibaf said Saturday that attacks on the country’s power plants would “immediately” be met with retaliatory strikes on energy and oil infrastructure across the region. “Critical infrastructure and energy and oil infrastructure throughout the region will be considered legitimate targets and irreversibly destroyed, and oil prices will rise for a long time,” Ghalibaf said on X. On Sunday, Ghalibaf extended the threat to holders of U.S. Treasurys, warning financial institutions that purchase American government bonds and “finance the U.S. military budget” would be considered legitimate targets, alongside military bases.