Filed gains instead of losses in 2018 (RobinHood)

[brownfox]

I incurred capital loss in 2018 due to selling stocks in December 2018. But when I was preparing my taxes, I did mention only capital gains (since at this time December transactions were not ready yet). So, I've filed about $700.00 of gains instead of real about $5000 of losses. What should I do now in 2020? Do I need to do an Amended Tax Return via TurboTax? Or any other advice? Thanks!

[MarilynG1]

Does your 1099-B say 2018? 

If so, you should Amend your 2018 return to report them.

Click this link for detailed instructions on How to Amend a 2018 Return. 

[brownfox]

1099-B 2018 says: 

Gain or loss(-) & 7- Loss not allowed (X) also not reported (Z) -$5,000.00 (Sale)

But for some reason, it doesn't show me other transactions for 2018. I can see them only in a separate document "CONSOLIDATED FORMS 1099-B 2018". That is where +$700.00 comes from.

This is kind of confusing since 1099-B 2018 has -$5,000.00, but CONSOLIDATED FORMS 1099-B 2018 has +$700.00 (which I did report)