You are not restricted to posting in the "headline" area of the "Let's Get You an Answer" page which only allows a limited number of characters. If you scroll down a bit on that page you'll see an "Add details to your question" box. That box provides plenty of room to add all sorts of pertinent detail and other information the the question you've posted.
I'm not sure what your question is here, exactly.
Same day sales typically do result in a small loss. If you didn't get a 1099-B in this case, (brokers aren't required to issue one in this situation), then you aren't required to report the sale. But you can report the sale if you wish by using the "Stocks, Mutual Funds, Bonds, Other" interview and telling TurboTax that no 1099-B was received.
If you did get a 1099-B but didn't report it under the mistaken belief that "the gain is already reported on my W-2" then you have two ways of going here:
- Amend your 2017 income tax return and take the small loss and receive an even smaller refund, or
- Don't amend and see if the IRS ever notices the the missing 1099-B. They might not. If they do notice it missing 1099-B and bill you for a "gain" - the difference between what you paid, (maybe nothing), and the selling price, then at that point you could chose to amend or attempt to explain the situation to the IRS with a well-written letter, backed up with documentation, that it was a same day sale that resulted in a small loss.
If none of the above answers your real question, then post back here with clarification.