SDIG

Stronghold Digital Mining, Inc.

A vertically integrated Bitcoin mining company that generates its own electricity by burning waste coal—the leftover refuse from Pennsylvania's historic coal mines—at its Scrubgrass and Panther Creek power plants, turning environmental hazards into energy for its mining data centers. Founded in 2021 by Gregory Beard and William Spence, the company went public on the Nasdaq that same year and was later acquired by the Canadian miner Bitfarms in 2025. Its name reflects its self-sufficient model: by owning its own power plants, it built a fortified "stronghold" against energy market swings while cleaning up legacy coal piles.