PayPal

Born in South Africa, studied physics and economics at the University of Pennsylvania, and began a PhD in applied physics at Stanford before dropping out after two days to pursue entrepreneurship. Co-founded Zip2, an online city guide software company, and sold it to Compaq for roughly $307M in 1999. Used those proceeds to found X.com, an online financial services company conceived as a "one-stop financial supermarket." X.com merged with Confinity—whose product, a money-transfer service called PayPal, was gaining traction—in 2000. Musk personally wrote early X.com code and pushed for a unified Windows-based platform, a technical stance that put him at odds with Confinity's founders. He was removed as CEO by the board later that year while on his honeymoon and replaced by Peter Thiel. The merged entity was renamed PayPal in 2001 and acquired by eBay in 2002 for $1.5B, with Musk, the largest shareholder, receiving roughly $165M.

Co-founded PayPal as Confinity alongside Peter Thiel, Max Levchin, and Luke Nosek while still a Stanford undergraduate (BS in Economics). Served as PayPal's first CFO through its 2002 IPO and $1.5B acquisition by eBay. After the exit, co-founded Founders Fund, the venture firm behind early-stage bets on SpaceX, Facebook, Palantir, and Airbnb. Later served as U.S. Ambassador to Sweden (2019–2021). Distinguished within the so-called "PayPal Mafia" not as a product or engineering lead but as the operational and financial backbone — the person who handled the mechanics of actually running and eventually selling the company.

Co-founded the company alongside a group that included Elon Musk, Peter Thiel, Max Levchin, and Ken Howery. Previously co-founded Fieldlink (later renamed PayPal) with Levchin, building early security and cryptography products that became the foundation of the payments platform. Studied at the University of Illinois at Urbana-Champaign. After eBay's acquisition of PayPal, co-founded Founders Fund, a venture capital firm known for backing transformative technology companies including Facebook, SpaceX, Palantir, and Airbnb. Also founded Halcyon Molecular, a longevity and genomics research company. Unlike some other PayPal alumni who maintain high public profiles, Nosek has been notably reserved — he rarely gives interviews and has described himself as more interested in building than being in the spotlight, yet he has shaped the thesis behind Founders Fund's bets on frontier technologies.

Born in Kyiv, Ukraine, moved to the US at age 16. Earned a B.S. in Computer Science from the University of Illinois at Urbana-Champaign, where he focused on cryptography and security. Co-founded Confinity in 1998 with Peter Thiel and Luke Nosek — the company started as a Palm Pilot cryptography venture before pivoting to the digital payments service that became PayPal. eBay acquired PayPal for $1.5 billion in 2002. Prior to Confinity, he had founded SponsorNet New Media, a web development business, while still in high school. Known as the deeply technical co-founder who personally wrote much of PayPal's early anti-fraud infrastructure, a security-first mindset that defined the company's risk management DNA.

A Stanford-educated lawyer (AB in Philosophy, 1989; JD, 1992) who clerked for Judge Richard Posner and worked at Sullivan & Cromwell before co-founding Confinity (later PayPal) in 1998. Earlier entrepreneurial attempts included running a small hedge fund, Thiel Capital. After PayPal's $1.5B sale to eBay in 2002, he co-founded Palantir Technologies and Founders Fund, and made the first outside investment in Facebook ($500K for ~10%). Known for a deeply contrarian worldview — he popularized the "zero to one" thesis, argues technological innovation has stagnated, and has been uncommonly willing to publicly break with Silicon Valley orthodoxy on politics, higher education, and the direction of the tech industry.