Assets that have lost value since purchase can be sold, and the capital loss can offset capital gains and up to $3000 of ordinary income. Tax losses can be claimed on individual equities/stock and stock funds. But don't forget that this can also be done with individual bonds and bond funds. Remember that you want to avoid the wash sale rule - you cannot purchase substantially the same asset 30 days before and after the loss sale; otherwise, the loss cannot be recognized.