(a) General.
(1) For income tax purposes, a short sale is not deemed to be consummated until delivery of property to close the short sale.
and this is another source where the year to report depends on whether you had a gain or loss.
In almost all cases, the trade date controls the tax-reporting year for a stock sale. That is, if you sell stock by the last trading day of this year, you report the sale on this year’s taxes. The exception occurs when you close out a short sale for a loss, in which case the settlement date controls the reportable tax year.
