When Surojit Chatterjee logs out on his final day as chief product officer at Coinbase on February 3, he will have made a whopping $105 million from stock sales.

According to disclosures filed with the Securities and Exchange Commission, the former chief product officer will also retain a further 249,315 shares of COIN stock, worth another $7.6 million. (Our estimates are based on the closing price of Coinbase stock, at $49.42 per share, on Friday, January 20, after the exercise price, which was $18.71.)

Chatterjee joined San Francisco-based Coinbase from Google in February 2020 on a salary of just under $1 million per year, the filings show.In April 2021, Bloomberg noted that Chatterjee's five-year contract with the company was worth $646 million. But his stay was cut short and the crypto market has crashed since, bringing down his total take-home.

That astronomical number in the five-year contract was driven by the rise of COIN stock. As the coronavirus pandemic raged across the planet, bored people stuck in lockdown turned to crypto in droves. The price of Bitcoin hit $69,000. Coinbase's revenues are heavily linked to crypto transaction volume, and COIN stock rocketed to a high of more than $342 per share during that year. Chatterjee's options were priced at just at $18.71 — making him fabulously wealthy.

That wealth wasn't just on paper. The company required its executives to trade their stock according to a Rule 10b5-1 plan, which generated frequent automatic sales of their options on a schedule they did not control. As the months went by, Chatterjee was granted options and then sold them in 65 separate transactions, mostly in 2021, according to his SEC disclosures. The plan paid off handsomely: He took $102.5 million in cash gains in 2021 alone.