Whats the last day to sell stock and still report the gain or loss in the current year. The answer is the last trading day of the year.

Trade date controls

When determining what year you sold your stock, the trade date is what matters. This is the day the transaction took place on the stock exchange. If you contact your broker on the last trading day of the year, you can complete a sale in the current year if your broker executes the trade that day. On major exchanges, the last trading day is December 31 unless that day falls on a weekend. It doesnt matter if your transactions settles in the following year. See Trade Date and Settlement Date .

Stock in the company where you work

If you own stock in the company where you work, chances are that the company permits sales only during certain periods, often called trading windows. Your last day to sell shares in the current year is the last trading day that occurs within a window period.

Exception for loss from short sales

In a short sale you sell shares borrowed from someone else rather than shares you already own. Typically youre expecting the stock to decline in value so you can make a profit by using shares bought later at a lower price to meet your obligation to restore the shares you borrowed when you made the short sale. When you buy shares to close a short position, this purchase (like any other) has a trade date and a settlement date. The date thats used for tax purposes depends on whether you have a gain or a loss:

• If youre closing the short position at a profit, the trade date controls the timing for tax purposes. In other words, we use the same rule here as when youre selling shares you own.
• If youre closing the short position at a loss, however, the settlement date will control.

When to report gain or loss

This peculiar result stems from an old IRS ruling and a more recent legislative development. The ruling noted that a short position isnt actually closed until you deliver shares to replace the ones you borrowed. You cant do that until your purchase of replacement shares closes, so thats when you report gain or loss from closing a short position, according to this ruling. In a later development, Congress added a constructive sale rule to the tax law. The main thrust of this rule is to require you to report capital gain thats built into an investment position as of the time you acquire an offsetting position. Shares of stock offset a short position in the same stock, so the purchase, which occurs on the trade date, can trigger built-in gain even though loss wont be reported until the short position is actually closed, on the settlement date.

• Bottom line. As a general rule you can continue to make stock transactions affecting your capital gain or loss for the year up until the last trading day of the year. If you want to claim a loss from a short sale, however, you have to act early enough so the transaction will settle by December 31.

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