Block began with a lost sale in 2009, when St. Louis glass artist Jim McKelvey could not take a credit card for a $2,000 set of glass faucets. He and Jack Dorsey, then also building Twitter, created Square, a small reader that plugged into a phone’s headphone jack. The real innovation was the software behind it: Square acted as merchant of record, absorbing risk, compliance and fraud detection so small sellers could skip bank merchant accounts. By summer 2010 it served 50,000 merchants with chargeback rates under 0.05 percent. Visa invested in 2011, and in 2012 Starbucks invested $25 million and had Square process its coffee sales. Square Cash launched in 2013 and grew into Cash App, with debit cards, direct deposit, stock and Bitcoin trading and tax filing, reaching 57 million active users by 2024, especially among lower-income and underbanked adults.

A buying spree followed: Weebly for $365 million in 2018, a majority of Jay-Z’s Tidal for nearly $300 million in 2021 and Afterpay for $29 billion in 2022. Square renamed itself Block in late 2021, drawing an H&R Block trademark suit settled in 2023. In March 2023 Hindenburg Research alleged inflated user counts and fraud on Cash App, claims Block denied, and in May 2024 reports said federal prosecutors were examining anti-money laundering and sanctions compliance. Block then narrowed its focus to Bitcoin and AI, launching the Bitkey self-custody wallet in 95 countries and designing its own 3-nanometer Proto mining chips. Its ticker changed from SQ to XYZ in January 2025, it joined the S&P 500 in July 2025, and in February 2026 it cut over 4,000 jobs, about 40 percent of staff, explicitly citing AI.

• Dorsey justified the Tidal deal by arguing that musicians are small businesses that need better financial tools.
• A DNS outage in September 2023 knocked out both Square merchant terminals and Cash App.
• Time named Bitkey one of the best inventions of 2024.
• Block’s shares jumped 24 percent after the February 2026 layoffs were announced.
• In July 2026 Block launched Buzz, a platform for AI agents to work alongside human employees.