You can claim a capital loss if a business you invested in files for bankruptcy and your stock is now worthless.
See How do I deduct worthless stock?
Creditors are often able to recover some amounts through the bankruptcy process so if you write off your entire investment, you may have to add back income in the future if you are paid anything back.
Filing an amended federal and state return will probably get you an additional refund. You can start the amend process in TurboTax to see the results. If you aren’t getting any money back, you can cancel your amendment.
See How do I amend my 2021 return?
