Because the stock loss produced a tax benefit to you, the recovery is taxable. The question is whether you report the recovery as a capital gain (since you took a capital loss) or as ordinary income. Under the “origin of the claim doctrine,” it appears that the recovery can be treated as capital gain even though the lawsuit recovery isn’t a sale or exchange. But the IRS has not ruled definitively on this exact situation.
Source: https://taxprof.typepad.com/taxprof_blog/files/2005-16770-1.pdf
Gross income less allowable adjustments, such as IRA, alimony, and Keogh deductions. AGI determines whether various tax benefits are phased out, such as personal exemptions, itemized deductions, and the rental loss allowance and modified adjusted gross income (MAGI).