The wash sale rule exists to stop a specific manoeuvre: selling something at a loss purely to claim the deduction, then immediately buying it back so your position is unchanged. For securities, a loss is disallowed if you acquire substantially identical property within a defined window around the sale.
Whether that rule reaches digital assets has been a live question, and the answer has practical consequences for anyone harvesting losses.
This is general information, not tax advice. Rules differ by jurisdiction and change; consult a qualified professional.
What changed in 2026
- Broker reporting expanded. Digital asset transaction reporting requirements increased what tax authorities receive directly, which raises the practical importance of getting treatment right.
- Legislative proposals persisted. Measures to extend wash sale treatment to digital assets continued to appear in tax proposals, keeping the position uncertain rather than settled.
- Cost basis tracking requirements tightened. Per-account and per-wallet basis tracking expectations became stricter, which affects how lots are identified.
- Enforcement attention grew. More reported data meant more matching against filed returns.
How the rule works for securities
| Element |
Detail |
| Triggering event |
Selling at a loss |
| Window |
A period both before and after the sale |
| What counts |
Substantially identical property |
| Effect |
The loss is disallowed, not lost |
| Where the loss goes |
Added to the basis of the replacement position |
| Accounts covered |
Includes other accounts you control |
The disallowed loss is deferred rather than destroyed — it increases the cost basis of the replacement holding, so you get the benefit when you eventually sell that. The rule delays the deduction rather than removing it.
The scope catches people. It covers purchases in other accounts you control, including retirement accounts and in some cases a spouse's accounts, which means a sale in a taxable account and a purchase in a retirement account within the window can trigger it.
The digital asset question
The distinction has rested on how digital assets are classified for tax purposes, which has historically placed them outside the category the wash sale rule addresses. That produced a difference in treatment that many practitioners viewed as a temporary gap rather than a stable policy.
Proposals to close it have appeared repeatedly in legislative packages. Whether any has been enacted for a given tax year is exactly the sort of thing that changes, and it is why relying on a general statement about treatment is unwise for a specific filing.
The practical implications are worth stating carefully. If the rule does not apply, harvesting losses on digital assets while maintaining a position is straightforward. If it does, the same activity produces disallowed losses and a nasty surprise. The difference is large enough to warrant confirming the current position rather than assuming continuity.
Note also that economic substance doctrines can apply independently of the specific rule. A transaction with no purpose other than generating a deduction can be challenged on other grounds.
Cost basis method matters regardless. Specific identification, where permitted and properly documented, gives control over which lots are sold and therefore what gain or loss is realized — the same mechanics discussed in tax-loss harvesting for securities.
Common mistakes
- Assuming the treatment is settled. It has been a moving target.
- Ignoring other accounts. For securities, the rule reaches accounts you control.
- Poor lot tracking. Without records you cannot identify which lots were sold.
- Treating a disallowed loss as lost. It adjusts basis; it is deferred.
- Harvesting without professional input at scale. The rules interact with your whole return.
FAQ
Does the wash sale rule currently apply to crypto?
This has been unsettled and subject to legislative change. Confirm the position for the specific tax year with a professional rather than relying on general guidance.
What counts as substantially identical?
For securities it is a narrower test than it sounds — different companies in the same sector generally do not qualify. For digital assets the question interacts with the classification issue.
Does this apply outside the United States?
Other jurisdictions have their own analogous rules with different names, windows, and scope. Local advice is essential.
Should I stop harvesting losses?
No, and do it with an understanding of current rules and good records rather than on assumptions.
Where to go next
For the securities version, read tax-loss harvesting and capital gains tax explained. For lot accounting in digital assets, crypto tax lots.