Jan Koum

Jan Koum (Yan Borysovych Kum, Ukrainian) is a Ukrainian-American businessman and engineer. He was born on February 24, 1976, and is the co-founder and former CEO of WhatsApp, a mobile messaging app that was acquired by Facebook in 2014 for $19.3 billion. According to Forbes, he is estimated to have a net worth of $13.8 billion as of September 2022.

Early life

Koum was born in Kyiv, then in the Ukrainian SSR, on February 24, 1976. He grew up in Fastiv. In 1992, at the age of 16, he moved with his mother and grandmother to Mountain View California. A social support program helped the family find a small two-bedroom apartment there. His father planned to join the family later, but it’s reported he never left Ukraine and later died in 1997. Koum and his mother stayed in touch with his father up until his passing. It’s reported that his mother may have worked as a babysitter while he worked as a cleaner at a grocery store, but this isn’t confirmed. His mother later died in 2000.


By the time Koum was 18, he had become interested in programming. He enrolled at the San Jose State University while simultaneously working at Ernst & Young as a security tester. He also joined w00w00, a computer security think-tank started in 1996, where he met future Napster creators Shawn Fanning and Jordan Ritter. In 1997, Koum met Brian Acton while working at Ernst & Young. Later that year, he was hired by Yahoo! as an infrastructure engineer. He quit school shortly after this. Over the next nine years, Koum and Acton worked at Yahoo! Together. In September 2007, the pair left and took a year off, traveling around South America while playing ultimate frisbee. Both applied to work at Facebook but were ultimately not accepted.

In January 2009, Koum bought an iPhone and realized that the then seven-month-old App Store was about to spawn an entirely new industry of apps. He visited his friend Alex Fishman and the two talked for hours about Koum’s idea for an app. Koum almost immediately chose the name WhatsApp because it sounded like “what’s up”. A week later, on his 33rd birthday, he incorporated WhatsApp Inc. in California.

WhatsApp was initially not very popular, but its fortunes began to turn after Apple added a push notification ability to apps in June of 2009. Koum changed WhatsApp to “ping” users when they received a message, and soon after he and Fishman’s Russian friends in the area began to use WhatsApp as a messaging tool in place of SMS. The app would gain a large user base, and Koum convinced Acton, then unemployed, to join the company. Koum granted Acton the status of co-founder after Acton managed to bring in $250,000 in seed funding.

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

In April 2018, Koum announced he was leaving WhatsApp and stepping down from Facebook’s board of directors due to disputes with Facebook. It was originally speculated that by leaving, he was forfeiting his unvested stock, worth almost $1 billion. However, a few months later, it was discovered he was still formally employed by Facebook, earning a reported $450 million in stock from the company through a method called “rest and vest.”

Koum is Jewish and is reported to dislike being called an entrepreneur, once tweeting: “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 solely by the desire to make money, whereas he has said that he only wants to build useful products.

Net Worth

$13.8 billion


In 2014, Koum donated $1 million to The Free BSD Foundation and close to $556 million to the Silicon Valley Community Foundation.
In 2016, The FreeBSD Foundation received a further $500,000 and additional donations from the Koum Family Foundation, including $750,000 in 2018 and $500,000 in 2019.
Koum also donated $2 million to AIPAC to support their involvement with the 2022 Democratic primaries.