A long as the stock exists, and it will until a company officially goes out of business (chapter 11, etc.) and recalls all of its stock from the existing shareholders. If a company simply goes “dark” like GNBT did before Joe took the reins, the stock still exists and is free to be traded according to market demand.
This is why the Grey Sheets exist https://www.extraordinaryinvestor.com/grey-sheets.html
There are a lot of companies listed on the OTC with little or no company info https://www.otcmarkets.com/research/stock-screener
NUGX isn’t even a legitimate stock ticker, yet it is still being traded.
So GNBT and NUGX will still be around if Generex should ever decide to quietly/secretly close their doors. Maybe the pps will languish with near zero volume or be subjected to a Pump and Dump scheme by a nefarious Day Trader. With no official corporate status updates, we are all playing dice in the dark.