The Idea: In 2012, two Brazilian teenagers got into a heated argument on Twitter about coding tools. The character limit wasn't enough to settle it, so Henrique Dubugras and Pedro Franceschi hopped on Skype instead. They instantly became friends. A year later, at just 15 and 16 years old, they launched Pagar.me - the "Stripe of Brazil." They scaled it to 150 employees and $1.5 billion in transactions before selling it for tens of millions in 2016. With cash in hand, they enrolled at Stanford - but lasted less than a year. The classroom couldn't compete with the startup itch. They joined Y Combinator with a VR idea, pivoted three weeks in when they realized they knew nothing about VR, and noticed a problem hiding in plain sight: none of their YC batchmates could get a corporate credit card. Banks saw startups as too risky. Henrique and Pedro saw an opportunity. This was the beginning of Brex.

The Execution:

• April 2017: Weeks before YC Demo Day, Ribbit Capital led a $7 million Series A into the fledgling company.
• June 2018: Brex launched to the public with $57 million in funding, spending $300K on billboards across San Francisco to get the word out.
• October 2018: Just 18 months after founding, Brex hit a $1.1 billion valuation with a $125 million Series C - making Henrique and Pedro some of the youngest self-made billionaires ever.
• April 2021: Tiger Global led a $425 million Series D at a $7.4 billion valuation as Brex expanded beyond startups to serve SMBs and enterprises.
• January 2022: Brex peaked at a $12.3 billion valuation after raising $300 million more - with 80% of YC companies and 25% of all US startups using their platform.
• January 2026: Yesterday, Capital One announced it's acquiring Brex for $5.15 billion in cash and stock - capping off a nine-year journey from teenage hackers to fintech legends.

The lesson? Henrique and Pedro didn't set out to build a $5 billion company - they set out to solve their own problem. When banks wouldn't give startups credit cards, they built one themselves. When VR didn't make sense, they pivoted in three weeks. When Stanford got boring, they dropped out. The best founders don't wait for permission. They see a broken system and fix it - even if they're teenagers arguing on Twitter.