A Global Market Based on Gold Bars Shudders on Tariff Threat

The global gold market relies on a network of banks, refineries and couriers that can fly bullion between key trading hubs at a moment’s notice in pursuit of the highest prices. On Friday, a shock US ruling suggesting that the metal would be subject to tariffs plunged that system into chaos.

The apparent decision by the US Customs and Border Protection agency — announced privately in a letter to a Swiss refiner on July 31 and made public Friday — sent gold futures in New York soaring to a record, as insiders warned the tariffs would have dire consequences for ...