The IRS allows victims of Ponzi schemes to deduct their losses as theft losses rather than as capital losses. While thefts of personal use property are currently barred (only disaster losses are allowed), thefts of investment property remain deductible as an itemized deduction. The IRS has guidance on determining the amount and timing of the losses as well as a safe harbor for determining the year in which the loss is deemed to occur.
Rules for determining whether a person is active in a business activity for passive activity rule purposes. Unless the tests are met, passive loss limits apply.