Bitcoin self-custody creates a massive cost-basis blind spot on your 2026 crypto tax forms

A Bitcoin investor can withdraw coins from an exchange, return them to the same account, and still fall outside mandatory cost-basis reporting when those coins are sold.For the 2026 US reporting year, the broker can still be required to report sale proceeds, while reporting the acquisition cost remains voluntary.Cost basis, the acquisition cost used to calculate a gain, only changes the broker's obligation to supply an ordinary transfer between the investor's own accounts. That creates a practical divide between a record showing how much a sale brought in and one that supports the gain calculation.The IRS's 2026 Form 1099-DA instructions make that divide explicit. Covered digital assets generally must have been acquired after 2025 in the reporting broker's custodial account and held there until disposal. Assets bought before 2026 or transferred into the broker are noncovered, with basis reporting voluntary.The distinction runs through the current reporting year as international reporting develops and blockchain analytics providers offer tax authorities a wider view of activity.Three routes, the same gainConsider a deliberately simplified hypothetical US investment: 0.1 Bitcoin boug...