What is Sophia's final net loss that she can deduct against other types of income for the year based on her trading results?

To determine Sophia's final net loss that she can deduct against other types of income, it's important to understand the limitations set forth by the IRS regarding capital losses. Individuals can typically offset capital gains with capital losses and can use any remaining losses to offset ordinary income.

In a calendar year, if the total net capital loss exceeds the $3,000 limit, only $3,000 can be deducted against other types of income for individuals who are filing as single or married filing jointly. This limit is set to prevent taxpayers from using a large capital loss to offset other income extensively.

In this scenario, regardless of the total losses Sophia realized from her trading activity—be it $12,000, $15,000, or any other amount—she is capped at deducting only $3,000 against her other income. Therefore, the correct answer reflects the IRS’s rules regarding capital gains and losses, which is why a deduction of $3,000 is appropriate in this context.