How to write off, on U.S. taxes, stocks that vanished due to company filing Chapt. 11?

Question

I don't have cost-basis information for the shares I lost either.

Answer 1

You report the sale on Schedule D as though you sold them for zero on the last day of the year. You're going to have to make a good faith effort to establish the cost basis. You know approximately when you acquired them, right? Go back and find out what the stock was selling for on that date. Most financial sites give you historical prices -- at least for a number of years. Otherwise see a brokerage like Charles Schwab, and they're likely to help you look it up. Keep in mind, that technically if you can't establish the cost, the IRS is entitled to presume it is zero also. But if you make a good faith effort to approximate it, they'll be reasonable about it.

Answer 2

If you don't have the cost basis information there's nothing that you can do.

You must claim the loss in the year that the stock was declared worthless.