Validity of bitcoin as a currency is irrelevant. What is relevant is that a US citizen can possess a cash-equivalent that behaves in a fashion similar to forei

Validity of bitcoin as a currency is irrelevant. What is relevant is that a US citizen can possess a cash-equivalent that behaves in a fashion similar to foreign currencies or commodities. The tax law is pretty clear on investments and cash-equivalents, bitcoin is both without addressing a question of currency status.