BBC World Service - Good Bad Billionaire

Elon Musk: Money, memes and Mars

How Elon Musk became the richest person on the planet

How fashion and controversy fuelled the rise of Luciano Benetton

How Tyler Perry went from living in his car to becoming a Hollywood mogul

How Lakshmi Mittal built a steel empire and reshaped an entire industry

How Michael O’Leary turned Ryanair into the largest airline in Europe by cutting costs

From teen mom to roofing mogul: how Diane Hendricks built a $22 billion empire

Norwegian shipping magnate John Fredriksen owned the world’s largest fleet of oil tankers

How disappearing messages app Snapchat made Evan Spiegel a billionaire at 25

How Tatyana Kim went from English teacher to head of Russian’s largest online retailer

Arnold Schwarzenegger, from Mr Universe to cinematic superstar and billionaire investor