Stripe is the payments and financial infrastructure backbone for internet businesses. Companies plug into Stripe's APIs to accept payments online and in person, manage subscriptions and invoicing, issue cards, move money across borders, detect fraud, and handle tax compliance. Its customer base spans early-stage startups through the Fortune 100 — half the Dow Jones Industrial Average runs on Stripe. The core business is payment processing (a percentage-of-transaction take rate), but Stripe has steadily expanded into adjacent financial services: corporate treasury, embedded banking, and revenue automation. More recently it has moved into stablecoins via its $1.1B Bridge acquisition and into AI commerce infrastructure via the ~$8B acquisition of OpenRouter (an AI model routing marketplace). Merchants in 50+ countries use the platform; total payment volume hit $1.9 trillion in 2025. Revenue products — billing, invoicing, tax — are on track to collectively hit a $1B annual run rate in 2026. The company is robustly profitable and has stayed private by using employee tender offers for liquidity rather than pursuing an IPO.