Block, Inc. (SQ), founded in 2009 by Jack Dorsey, is a fintech company integrating Bitcoin into financial services via Cash App and Bitkey. It holds 8,584 BTC as of December 31, 2024, valued at $720.8 million at $84,000/BTC, representing 0.041% of Bitcoin’s supply. Listed on NYSE, it invests 10% of monthly Bitcoin product profits into Bitcoin since October 2020.