Fidelity updated a1099. Should I simply re-import it (will it only import the new information) OR, delete the original import and import the updated 1099 again? TIA

Delete the original and manually enter the revised form.   In most cases only the original is available for import.

You may delete and re-import the financial data or you can simply update the 1099 in question.

• See How do I update or delete something I imported into TurboTax?

If you have 1099-B forms, your total capital gains for the year minus your total capital losses result in a net gain or a net loss.

• You can deduct a net loss of up to $3,000 ($1,500 if married filing separately). Any capital loss you couldn't deduct this year can be carried forward and deducted on future tax returns as a capital loss carryover.