US gold tariffs jolt COMEX, shift global trade flows

The Trump administration’s move to apply import duties on the most common forms of bullion delivered into the United States is shaking the gold market and widening the price gap between New York and London.

A ruling by the U.S. Customs and Border Protection agency confirmed that 1-kg. and 100-oz. bars fall under a customs code subject to reciprocal tariffs. The decision was issued in response to a request from a Swiss refinery seeking clarity on the new trade rules.

Market participants had assumed these bar sizes would be exempt under an April list that spared certain non-monetary gold from tariffs. Instead, the agency classified them under a separate category not included in the exemption, overturning long-held expectations. BMO Capital Markets said the clarification is already changing market behaviour.

“We would expect U.S. prices to come under upward pressure as the market prices in a higher delivered cost of metal to COMEX,” the bank said in a note on Friday. “With gold being such a liquid market, global flows are likely to adjust towards the origins subject to the lowest U.S. tariffs.”

The immediate impact was seen in early trading, with COMEX gold futures rising by more than 1%, outpacing gains in London spot prices and widening the spread between the two benchmarks. COMEX gold futures for December delivery are trading at about $3,499.30 per ounce, after touching an intraday high of $3,534.10. In London, spot gold is around $3,395 per ounce.

Different sizes

The main COMEX GC Gold contract allows for delivery of 100-oz. and 1-kg. bars. A less liquid Enhanced Delivery contract accepts 400-oz. bars, the standard unit in the London over-the-counter market.

Earlier this year, concern that tariffs could be applied to bullion prompted refiners to convert London bars into COMEX sizes. That pulled metal away from Europe towards Swiss plants, which recast them for the U.S. futures market.

The move is a blow to Switzerland, the world’s largest gold exporter. The country supplied 12% of US imports last year and has been a key hub for converting 400-oz. London bars into the smaller units needed for COMEX delivery. The change in tariff treatment could make Swiss shipments less competitive compared with sources facing lower or no duties.

The United States imported 220 tonnes (7.1 million oz.) of gold in 2024. Canada accounted for 27% of shipments, followed by Mexico and Colombia at 18% and 12% respectively, with Switzerland also at 12%.

COMEX inventories have rebounded in recent weeks, rising by about 2 million oz. since mid-July to nearly 39 million oz. That follows a drawdown in May and June after the April tariff announcement, when traders positioned for possible supply disruptions.

BMO said the current stockpile could help temper near-term volatility. But the new tariff regime raises questions over New York’s long-term role as a global bullion hub, given the higher cost base compared with other trading centres.