Elon Musk's rollercoaster week: from rocket explosions to Twitter checks.

Elon Musk lost almost $13 billion in a single day due to a SpaceX rocket explosion and disappointing earnings report from Tesla. Much of Musk's wealth is derived from shares in Tesla, which tanked nearly 10% on Thursday on the back of a disappointing quarterly earnings report. Musk's net worth is now estimated to be $164 billion, down from $260 billion a year ago. Despite remaining one of the richest people on the planet, Musk's wealth has fallen drastically on the back of his Twitter acquisition and a raft of problems at Tesla, including slowing sales.