This tax season — the one that just ended for those lucky enough to have filed on time, and the one still painfully dragging on for those who filed for an extension — is the first for which brokers are required to report cost basis, in addition to gross proceeds, on Form 1099-B. An important part of the requirement is that brokers must apply the wash sale rule, which prevents you from claiming a loss on a sale of shares if you buy identical shares within 30 days before or after. Anyone who does a lot of buying and selling might wonder whether the broker applied this rule correctly. You may be surprised to learn that there’s no way to be sure. The wash sale rule is a lot more complicated than it appears, and there are unanswered questions about some aspects of its workings. (more…)

