Wheaton Precious Metals International Ltd. will pay $4.3 billion in upfront cash to acquire BHP’s 33.75 percent silver stream at the Antamina mine in Peru, increasing its total streaming interest to 67.5 percent. The Silver Stream, effective April 1, 2026, covers 100 million payable ounces at a 90 percent factor, then shifts to a 22.5 percent life-of-mine stream.

The acquisition immediately adds approximately 6 Moz of attributable silver production per year for the first five years and 5.4 Moz annually over the first ten years. Combined with the existing stream, total annual production averages 12 Moz for five years and 10.8 Moz for ten years, with ongoing payments equal to 20 percent of spot silver price.

Incremental exposure to Antamina boosts proven and probable silver reserves by 66 Moz, measured and indicated resources by 38 Moz, and inferred resources by 110 Moz. Current declared reserves support mining activities through 2036, with potential infrastructure expansions and regional exploration expected to extend mine life further.

The transaction increases Wheaton’s 2026 production by 11.3 percent on a pro-forma basis while representing 6.5 percent of its market capitalization. By 2030, Antamina is projected to contribute about 18 percent of total gold-equivalent production, and approximately 76 percent of 2026 output will come from first-quartile cost-curve mines.