After taking a capital loss, you can’t buy back the same security within 30 days. If you do, you will have a “wash sale” and the capital loss won’t count, for tax purposes. The same is true if you buy a stock and then sell other shares at a loss within 30 days.
There are ways you can proceed if you want a capital loss to count:
1. Wait. You might sell a bank stock at a loss, for example, and buy it back more than 30 days later. However, you’d miss some gains if the stock suddenly rebounds.
2. Buy something else. You can invest in another security–even another bank stock–right away. The other stock might do the same as the one you sold, do better, or do worse.
3. Double up. Say you own 100 shares, now trading at much less than what you paid. You could buy another 100 shares. After waiting more than 30 days, you can sell your original shares and take a tax loss. However, you must buy the replacement shares before the end of November if you want to take a tax loss the same year.