Jack Dorsey — Co-founder, Block (formerly Square) & Twitter

**Jack Dorsey** is the co-founder and Chairman of **Block, Inc.** (formerly Square), the financial technology company that has democratized payment acceptance for small businesses (Square), built a consumer financial super-app (Cash App), and invested heavily in Bitcoin through its Bitcoin mining hardware (Proto), Bitcoin exchange, and the TBD open-source Bitcoin development platform. He is also the co-founder of Twitter (now X), which he led as CEO twice before departing in 2021.