Equity "going to 0" is a consequence of a court proceeding called "bankruptcy". It is the courts of law that approve the deletion of equity. So not sure whom are you going to sue.
It will not go to $0. It will simply stop existing. You are free to trade it until then.
Lots of companies enter bankruptcy, are restructured, and emerge from the process without equity being destroyed. There is certainly some chance that happens here.
It will not go to $0. It will simply stop existing. You are free to trade it until then.