A capital loss won’t count, for tax purposes, if you buy the same security within 30 days of taking the loss. One way to avoid a so-called “wash sale” is to buy the same security at least 31 days before you sell.
Suppose, for example, you own 100 shares of a bank stock that is trading at a much lower price now than what you paid. You could buy another 100 shares of the same bank stock. Thirty-one (or more) days later, you can sell the 100 shares you bought first.
If your first 100 shares of that bank stock are still trading at a loss, you will have a capital loss that can offset capital gains. You’ll still own 100 shares of that same bank stock, from your second purchase, so you will profit if the stock rebounds.
To use this tactic this year, you must buy the second lot before the end of November. Then you can sell the first lot later in the year and claim a capital loss for this year.