Do I need proof of my ownership of the stock, and what is the best form of that proof?
Yes. While the best evidence of ownership are the confirmation slips received when you purchased the stock, you may also use your brokerage statements indicating when you bought the stock and at what price. You should be sure to keep these records in a safe place. You may need to submit them to the claims administrator after the case has been resolved. You will receive notification by mail when it is time to send in this documentation.