While this is a large number, this pay plan was actually very simple: Elon Musk would receive a small salary - as in comparable to what a middle manager at most fortune 100 companies would receive. The huge numbers only applied if Tesla's market capitalization hit certain thresholds, and then they were in the form of stock and not cash. The common wisdom in 2018 was that Tesla would never reach any of these market capitalization thresholds. Therefore, the risk was entirely on Musk's side and none of the side of the shareholders.