it's unusual for there to be any remaining basis when the business folds especially if you were the only stockholder. in such situations, losses and distributions would reduce your basis to zero. the situations where it could happen: you weren't one of the original investors (multiple stockholders). you inherited the S-Corp stock with a stepped-up basis. you contributed cash and/or property that was disproportionate to your ownership (multiple owners). bad bookkeeping/errors in return/k-1 preparation. anyway, if you have a remaining basis it's a capital loss reported on schedule D/form 8949
