I am going to assume that you do not qualify for trader tax status, and that you are not using the mark-to-market election.
Even if you think of yourself as a "day trader," or a "professional trader," or an "active trader," and even if you are subject to the pattern day trader rules in the USA, this does not make you a trader in the eyes of the IRS. Most retail traders in the USA are treated as ordinary investors under federal tax law.
In general, for investors, gains and losses are netted out for the calendar year.
If you have gains of $10,000 and losses of $6,000, you will report a net capital gain of $4,000.
The limitation of $3,000 per year only comes into play when you have a net loss for the year.
If you have gains of $6,000 and losses of $10,000, then you have a net loss of $4,000 for the year. You will be allowed to deduct $3,000 to offset other types of income (such as wages, retirement income, rental income, etc.). The remaining loss--$1,000 in this example--is carried forward to next year. It will be available next year to offset gains or other types of income.
As an additional example: Say you have $10,000 in gains and $20,000 in losses. So you have a net loss of $10K. You take $3K this year, and carry forward $7K in losses to next year. Next year, you have $15K in gains, and $5K in losses, for a net gain of $10K. But you get to apply the $7K carryforward, giving you a net gain for the year of just $3K.
BMK