Global markets tumbled after the cancellation of the planned summit between Presidents Trump and Xi, heightening trade tensions and uncertainty. The situation worsened as China imposed new export controls on rare earth minerals and launched antitrust probes into major U.S. chipmakers, including Qualcomm. The developments deepened fears of a prolonged U.S.-China economic standoff, triggering sharp declines in semiconductor and manufacturing stocks worldwide as investors rushed toward safe-haven assets amid rising geopolitical and supply-chain risks.