Gold Resource Corporation (NYSE:GORO) (the "Company," "we," "our," or "GRC") announced that it has received notification from the FTSE Russell that following the Company’s previously announced merger (the "Merger") with Goldgroup Mining Inc. ("Goldgroup"), the combined company will not be eligible for inclusion in the Russell 2000 Comprehensive Factor Index beginning on July 20, 2026, as Goldgroup does not meet FTSE Russell’s nationality eligibility requirements within the Russell Index family, apparently based on Goldgroup’s Canadian home country indicators. Previously, GRC had been added to certain Russell Indexes effective after the market close on June 26, 2026 in connection with the annual and semi-annual Russell U.S. Indexes reconstitution. Subject to obtaining all required approvals and the satisfaction or waiver of all required closing conditions for the Merger, the Merger is expected to be consummated after the market close on July 17, 2026.