Zacharty Kirkhorn, who stepped down as the chief financial officer of Tesla Monday, is leaving with a fortune of $590 million, Bloomberg reports.

Most of that money is tied up in Tesla shares and options Kirkhorn received during his four-year stint as CFO. His boss, Tesla CEO Elon Musk, is worth $230.6 billion, according to the Bloomberg Billionaires Index.

Tesla’s board of directors is largely responsible for Musk’s colossal wealth, as they awarded him an enormous pay package in 2018.

In 2022, Kirkhorn was paid a salary of $300,000 and accrued $31,099 in time off that he applied to the purchase of a Tesla, according to a Tesla proxy filing.

Kirkhorn, who has degrees from Harvard and the University of Pennsylvania, began working for Musk in 2010. Analysts have called the engineer, in his late 30s, calm and measured—a welcome contrast to his outspoken, bombastic boss.

Kirkhorn began his career as a Microsoft intern and as a McKinsey analyst.