Jan Koum (Ukrainian: Ян Кум; born February 24, 1976) is a Ukrainian American billionaire businessman and computer engineer. He is the co-founder and former CEO of WhatsApp, a mobile messaging application which was acquired by Meta (formerly Facebook) in February 2014 for US$19.3 billion. According to Forbes, he has an estimated net worth of US$10.7 billion as of January 2022.

Jan Koum
Ян Кум
Jan Koum (cropped).jpg
Koum, in 2013
Born (1976-02-24) February 24, 1976 (age 45)
Alma materSan Jose State University (dropped out)
Known forCo-founded WhatsApp with Brian Acton in 2009

In 2014, he entered the Forbes list of the 400 richest Americans at no 62, with an estimated net worth of $7.5 billion, the highest-ranked newcomer to the list that year.[1] As of January 2022, his net worth was estimated at $10.7 billion making him one of the richest people in the world.[2]

Early life and careerEdit

Koum was born in Kyiv, Ukraine, then in the Soviet Union. He is of Jewish origin.[3] He grew up in Fastiv, outside Kyiv, and moved with his mother and grandmother to Mountain View, California in 1992,[4] where a social support program helped the family to get a small two-bedroom apartment,[5] at the age of 16. His father had intended to join the family later, but he never left Ukraine,[6] and died in 1997.[5] Koum and his mother remained in touch with his father until his death.[7] At first Koum's mother worked as a babysitter, while he himself worked as a cleaner at a grocery store. His mother died in 2000 after a long battle with cancer.[citation needed]

By the age of 18 Koum had become interested in programming. He enrolled at San Jose State University and simultaneously worked at Ernst & Young as a security tester.[5] He also joined a group of hackers that began in 1996 called w00w00, where he met[5][8] the future founders of Napster, Shawn Fanning and Jordan Ritter.

In February 1996, a restraining order was granted against Koum in state court in San Jose, California. An ex-girlfriend detailed incidents in which she said Koum verbally and physically threatened her. In October 2014, Koum said about the restraining order, "I am ashamed of the way I acted and ashamed that my behavior forced her to take legal action".[9]

In 1997, Koum met Brian Acton while working at Ernst & Young as a security tester.[5]


Later in 1997, Koum was hired by Yahoo! as an infrastructure engineer. He quit school shortly thereafter.[5] Over the next nine years, Koum and Acton worked there together. In September 2007, they both left Yahoo! and took a year off, traveling around South America and playing ultimate frisbee. Both applied to work at Facebook, and both were rejected.[5]

WhatsApp and FacebookEdit

In January 2009, Koum bought an iPhone and realized that the then seven-month-old App Store was about to spawn a whole new industry of apps. He visited his friend Alex Fishman and they talked for hours about Koum's idea for an app.[5] Koum almost immediately chose the name WhatsApp because it sounded like "what's up", and a week later on his birthday, February 24, 2009, he incorporated WhatsApp Inc. in California.[5]

WhatsApp was initially unpopular, but its fortunes began to turn after Apple added push notification ability to apps in June 2009. Koum changed WhatsApp to "ping" users when they received a message, and soon afterward he and Fishman's Russian friends in the area began to use WhatsApp as a messaging tool, in place of SMS.[5] The app gained a large user base, and Koum convinced Acton, then unemployed, to join the company. Koum granted Acton co-founder status after Acton managed to bring in $250,000 in seed funding.[5]

On February 9, 2014 Zuckerberg asked Koum to have dinner at his home, and formally proposed Koum a deal to join the Facebook board. Ten days later Facebook announced that it was acquiring WhatsApp for US$19 billion.[10][11][12][13][14]

Over the first half of 2016, Koum sold more than $2.4 billion worth of Facebook stock, which was about half of his total holdings.[15]

In April 2018, Koum announced that he was leaving WhatsApp and stepping down from Facebook's board of directors due to disputes with Facebook.[16] It was originally thought that by leaving he was forfeiting his unvested stock, worth almost $1 billion.[17] However, several months later it was discovered that he was still formally employed by Facebook, earning a reported $450 million in stock from the company through a method called "rest and vest."[18][19]


Koum dislikes being called an entrepreneur, going so far as to post on Twitter in 2012, "Next person to call me an entrepreneur is getting punched in the face by my bodyguard." He feels that he is not an entrepreneur because entrepreneurs are motivated by the desire to make money, whereas he only wants to build useful products.[20]

In 2017, Koum began posting messages on Facebook in support of U.S. President Donald Trump. In September 2017, he wrote on Facebook, "as somebody who grew up in Soviet Union, Donald Trump couldn't be more right about failures of socialism...".[21]

Charitable actionsEdit

In November 2014, Koum donated $1 million to The FreeBSD Foundation, and close to $556 million to the Silicon Valley Community Foundation (SVCF) the same year.[22] In December 2016, Koum donated another $500,000 to The FreeBSD Foundation, followed by $250,000 donations in 2018 and 2019[23]


  1. ^ Forbes Announces Its 33rd Annual Forbes 400 Ranking Of The Richest Americans; 29 September 2014, Forbes.com, accessed 12 November 2014
  2. ^ "Forbes profile: Jan Koum". Forbes. Retrieved August 13, 2020.
  3. ^ "WhatsApp Founder Jan Koum's Jewish Rags-to-Riches Tale". The Jewish Daily Forward. Reuters. February 20, 2014. Retrieved March 1, 2014.
  4. ^ Rowan, David (February 19, 2014). "WhatsApp: The inside story (Wired UK)". Wired UK. Wired.co.uk. Retrieved February 20, 2014.
  5. ^ a b c d e f g h i j k Parmy Olson (February 19, 2014). "Exclusive: The Rags-To-Riches Tale Of How Jan Koum Built WhatsApp Into Facebook's New $19 Billion Baby". Forbes. Retrieved February 20, 2014..
  6. ^ WhatsApp: Jan Koum – The Story Of A Man Who Kept It Simple, Jewish Business News, Feb 20th, 2014
  7. ^ Olson, Parmy. "Exclusive: The Rags-To-Riches Tale Of How Jan Koum Built WhatsApp Into Facebook's New $19 Billion Baby". Forbes. Retrieved August 10, 2018.
  8. ^ "January Kum: communist Ukraine to 19 billion Whatsapp | Network 2". June 15, 2014. Archived from the original on June 15, 2014. Retrieved September 28, 2017.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  9. ^ De Jong, David (October 20, 2014). "Facebook's Jan Koum Apologizes for Past Restraining Order". Bloomberg.
  10. ^ Olson, Parmy (February 24, 2009). "Exclusive: The Rags-To-Riches Tale Of How Jan Koum Built WhatsApp Into Facebook's New $19 Billion Baby". Forbes. Retrieved February 20, 2014.
  11. ^ "Facebook acquires WhatsApp in massive deal worth $19 billion - ABC News (Australian Broadcasting Corporation)". Abc.net.au. February 20, 2014. Retrieved February 20, 2014.
  12. ^ "WhatsApp Founders Are Low Key — And Now Very Rich". Mashable.com. October 26, 2013. Retrieved February 20, 2014.
  13. ^ "WhatsApp's Founder Goes From Food Stamps to Billionaire". Bloomberg News. Retrieved February 20, 2014.
  14. ^ Wood, Zoe (February 20, 2014). "Facebook turned down WhatsApp co-founder Brian Acton for job in 2009". The Guardian. Retrieved February 21, 2014.
  15. ^ "Jan Koum Insider Trading Overview". www.insidermole.com. Retrieved September 28, 2017.
  16. ^ Dwoskin, Elizabeth (April 30, 2018). "WhatsApp founder plans to leave after broad clashes with parent Facebook". Washington Post. ISSN 0190-8286. Retrieved April 30, 2018.
  17. ^ "Next change for Facebook: New board director, executives reshuffled". The Mercury News. May 8, 2018. Retrieved May 9, 2018.
  18. ^ Salinas, Sara (August 15, 2018). "The WhatsApp founder who left Facebook is still employed, in an apparent move to vest stock". CNBC. Retrieved August 16, 2018.
  19. ^ Leswing, Kif (August 15, 2018). "The billionaire cofounder of WhatsApp is 'resting and vesting' — showing up to Facebook and barely working to collect a $450 million payday". Business Insider Singapore. Retrieved August 16, 2018.
  20. ^ "Why WhatsApp's Founder Hates Being Called An Entrepreneur". Retrieved July 22, 2016.
  21. ^ Wong, Joon Ian. "One of WhatsApp's founders still uses Facebook—to share pro-Trump stories". Quartz. Archived from the original on March 21, 2018.
  22. ^ "No. 4: Jan Koum - Philanthropy". Philanthropy.com. February 8, 2015.
  23. ^ "Foundation Announces New Uranium Donor". FreeBSD Foundation.

External linksEdit