Jan Koum

Jan Koum is the co-founder of WhatsApp, the encrypted messaging application he built with Brian Acton starting in 2009 and sold to Facebook (now Meta) in February 2014 for approximately $19 billion in cash and stock — one of the largest technology acquisitions in history and the transaction that made Koum one of the wealthiest immigrants in American history. Born February 24, 1976, near Kyiv in the Ukrainian Soviet Socialist Republic — his father was Jewish, his mother Ukrainian — Koum grew up in a village without hot water and in a family that like many Soviet Jews kept Jewish identity quiet under Soviet pressure. In 1992, at age 16, he immigrated to the United States with his mother, settling in Mountain View, California, where they lived on food stamps while Koum taught himself computer networking by buying manuals from a used book store and returning them after reading them. He attended San Jose State University and worked at Ernst & Young before joining Yahoo as an infrastructure engineer in 1997, where he met Acton.

Koum's Jewish identity — shaped by the Soviet Jewish experience of religious and ethnic suppression, immigration, and reinvention in America — has informed his philanthropic priorities, which have included significant giving to Jewish and Israeli causes alongside his broader technology and privacy-focused philanthropy. He has donated to organizations working on antisemitism and Holocaust remembrance, and has spoken publicly about his family's experience as Soviet Jews in terms that reflect a deep personal identification with Jewish collective vulnerability and the importance of Israel as a refuge. The WhatsApp encryption architecture — end-to-end encryption as a default, privacy as a design philosophy — is often described by Koum in terms of his childhood experience in a surveillance state, a biographical framing that connects his personal history as a Soviet Jewish immigrant to the product's foundational values.

Koum resigned from Meta's board of directors in 2018 over disagreements with Facebook's approach to data privacy and its push to monetize WhatsApp — a departure that maintained his credibility as a principled privacy advocate rather than simply a successful exit operator. His net worth, estimated at over $10 billion following the Facebook acquisition and subsequent stock holdings, has given him the philanthropic capacity to be a significant donor to causes he cares about without the public profile of an activist investor. His car collection — one of the most significant collections of vintage Porsches in private hands — and his low-profile lifestyle in the San Francisco Bay Area give him a distinctly different public image from the other technology billionaires on this list. At Rank 100, Koum is the Iron 100's only representative of the Soviet Jewish immigrant experience — the boy from a Ukrainian village without running water who built the world's most widely used encrypted messaging platform, and whose Jewish identity and philanthropic commitments complete the Iron 100's picture of who, in 2026, makes up the pro-Israel coalition in America.