When his net worth hit $150 billion on Monday, Amazon CEO Jeff Bezos became the richest person in modern history. The 54-year-old is already the richest person in the world, with his net worth increasing by $52 billion this year. Taking into account inflation, his $150 billion fortune is more than the $100 billion Microsoft co-founder Bill Gates had in 1999, which would be worth $149 billion today, USA Today reports. Bezos' staggering amount of wealth puts him well above his peers, including Gates ($93 billion), Berkshire Hathaway CEO Warren Buffet ($83 billion), Facebook CEO Mark Zuckerberg ($83 billion), and Inditex founder Amancio Ortega ($75 billion).