...

[Bsch4477]

You will receive a 1099-B from your brokerage. Report that in TurboTax and the program will do all the calculations for you. 

[VolvoGirl]

You only enter your actual sales.  Then it will calculate your overall gain or loss.  THEN If you have a net loss you can only deduct up to 3,000 per year.  The rest you will have to carryover until it is used up.  

[ra008]

...

[Mike9241]

You are leaving out something because your numbers don't make sense. Don't know how important this is.

if you put in 10K and had a realized profit of 3K you should have cash of 13K. To have a negative cash of 7K would mean either you withdrew cash and/or you bought securities of about 20K that haven't been sold and/or you had a loss of 17K or something else. We don't know what you are trading. This may be important if you're trading commodities and/or are doing hedging transactions.  The reporting may not be as simple as reporting the profit/loss on closed positions. 

[ra008]

...

[Bsch4477]

We’re confused. 
1. A U.S. brokerage will send a 1099-B. 
2.  If you put 10K into an account to invest and you made a profit of 3K why do you not have 13K?  What happened to the other 7K?

[Mike9241]

@Bsch4477 I think he mentioned that it's a foreign brokerage so no 1099.

Yes, we are confused by his math. As noted, if you start with 10K and add 3K that's 13K but for whatever reason he's subtracting the 3K. I suppose it doesn't matter. His responsibility is to properly report gains and losses. Cash and positions in his account don't matter except for possible foreign account reporting purposes.