The youngest billionaires in the world in 2018

 Spiegel cofounded the popular photo-sharing app Snapchat with his former Stanford classmate and fraternity brother Bobby Murphy in 2011.
When Snap began trading in March 2017, he became the youngest public company CEO.
Spiegel and Bobby Murphy each own around 18% of Snap but have voting shares that give them control over the board.

4. Evan Spiegel, 27 — $4.1 billion (£3 billion).