@davidL88 My observations based on my return:
TT: TurboTax
TA: ???? (probably can't name it here, but should be easy to guess)
The 3 columns of interest are "proceeds", "cost" and "gain/loss".
TT: it seems to start with "proceeds" and "cost" columns, and rounds each. This introduces error. It then uses these rounded values to compute the "gain/loss". This introduces even more error.
TA: it seems to start with the directly imported "gain/loss" column, and rounds. It then works backwards to adjust "proceeds" and "cost" columns if necessary in order to balance each line entry so that proceeds-cost=gain/loss. It's possible that it might also round the "proceeds" and "cost" entries, but then again it might not....again I think the software just trying to balance out each line at this point.
Overall, TA appears to work better since it seems to start with the "gain/loss" column (although it does too round here). The totals is still off by 1 or 2 dollars on the short term capital gains for me vs 10's of dollars for TT. But again, there appears to be less error involved here since it seems to start with actual imported "gain/loss" value.
