Development-stage mining company Sunshine Silver Mining & Refining files for an estimated $400 million IPO
IPO Overview
Sunshine Silver Mining & Refining, a development-stage mining company with a project in Idaho, filed on Monday with the SEC to raise up to what we estimate could be $400 million in an initial public offering.
Sunshine Silver Mining & Refining owns and is developing the Sunshine Mine and related refining facilities in Kellogg, a historically producing silver mine with byproducts including antimony, copper, and lead. The company is focused on maintaining and modernizing the site in preparation for a planned restart of mining, milling, and refining operations. Operations are currently on care and maintenance, with a restart targeted for 2028.
The Kellogg, ID-based company was founded in 2010 and plans to list on the NYSE under the symbol SSMR. Sunshine Silver Mining & Refining filed confidentially on December 18, 2025. Morgan Stanley, Scotia Capital, BMO Capital Markets, Canaccord Genuity, Citi, and RBC Capital Markets are the joint bookrunners on the deal.
About the Company
We are the owner and developer of the permitted Sunshine Mine and the Sunshine Silver/Copper Refinery, as well as the associated facilities including the Sunshine Tailings Storage Facility and historical antimony refinery grounds. The Sunshine Mine is a historic, permitted, large-scale past-producing silver mine in the United States, which historically also produced meaningful quantities of antimony, copper and lead. The Sunshine Mine is one of the highest-grade primary silver resources in the world, with an average diluted silver grade of 1,022 grams per tonne of Indicated Mineral Resources and 776 grams per tonne of Inferred Mineral Resources. When production is restarted, we expect the Sunshine Mine will also be one of the largest silver mines in the United States. We have the major permits required to restart mining, milling and refining operations, and we will not require an environmental impact study to initiate restart of such operations. Our mining, milling and refining complex includes substantial installed infrastructure, including approximately $208 million of investments that we have made over the last 16 years to maintain and modernize the Sunshine Complex and to consolidate the highly prospective land package surrounding the Sunshine Mine. We plan to restart operations at the Sunshine Complex in 2028.