High-volume traders are the most likely to trigger wash sales — and the least likely to realize it before tax season. The 30-day window is wider than most traders expect, the disallowed-loss mechanics compound across the year, and the situations that trigger them are surprisingly easy to miss.
This article walks through the rule itself — defined by the IRS in Publication 550 — the common scenarios active traders run into, and the workflow checks that prevent surprises in April.
What this article will cover
- The 30-day window — before AND after the loss-realizing trade.
- How the disallowed loss is added to the cost basis of the replacement shares.
- Substantially identical securities — what counts and what doesn't.
- Cross-account triggers (joint account, IRA, spouse's account).
- The end-of-year wash-sale check that high-volume traders should run every December.
Important: this article will be educational only and is not tax advice. Wash sale rules are nuanced and fact-specific. Consult a qualified tax advisor for guidance on your specific situation. Success Trader and Regal Securities do not provide tax advice.