Elon had the idea for an online banking system way back during his interning days, and gave form to the concept. A rival had appeared known as Confinity, which had a money-transfer service known as PayPal. Both companies had merged, leaving Elon as CEO and with 11.7% ownership over the newly named PayPal.
Musk had often disagreed with other company leaders, and was found to not be suitable enough as CEO. Peter Thiel, the co-founder of Confinity took his place.
One of the primary reasons for Elon's removal was due to his views on switching their operating system from a unix-based structure to Microsoft Windows.
PayPal was sold to eBay for $1.5 billion, of which Elon had secured $250 million, which after tax was $170 million.