It looks like a big chunk of his networth is included in the spin-off company of VMWare, which was acquired by Broadcom in exchange for 22M Broadcom shares. Broadcom has seen a boom in its own stock price and now enjoys a $1T market cap.
Ahhh damn, large company. Otherwise if you found a company that goes out of business and then personally recover financially to a positive net worth you can be like Michael Dell!