The number of billionaires is growing. Forbes released its World's Billionaires List Monday, with more than 1,800 billionaires making the list this year. Let's jump to the top 5 richest billionaires. Starting the list at number 5, Larry Ellison. The founder of technology company Oracle is worth more than $54 billion. Coming in at number 4, Amancio Ortega. The Spanish co-founder of clothing retail chain Zara, has a net worth of $64.5 billion. At number 3, Warren Buffett. The world's most successful investor moved up one slot this year, with a net worth of almost $73 billion. Number 2 on the list, Carlos Slim. The Mexican telecommunications mogul has a net worth of over $77 billion. And finally, the world'd richest person, Bill Gates. Forbes says the Microsoft co-founder's net worth rose to over $79 billion in 2015, from $76 billion last year. He has topped the list for 16 of the last 21 years.