To close this out, my thoughts align with elt894: Gainskeeper explicitly states they cannot handle this, though I see a whitepaper suggesting their institutional product can. I contacted Tradelog; they can't handle straddles. Tradelog even notes that you can't even import 6781 part 1 info into your tax return; you must copy paste it (not a big deal as you don't need to go line by line if your 1099-b has the data). I looked into Intuit's TurboTax TXF importing format and there is no way you could use that to import 6781 data. I have no idea if other commercial software would allow 6781 part 2 imports, but I'm dubious based on what I've seen. So as elt894 notes, the answer is just paper filing. This whole thing is a bit of fascinating learn on IRS enforcement. While tax straddle rules are only an issue if you either A) have some positions that are long term or B) dispose one leg for a loss in one year and a second leg for a gain in the next, I suspect many traders here have done at least B. (Basically any complex option strategy - option straddles, protected puts, etc. are all in the realms of tax straddles. If you've even sold for a loss on one side and waited until the next year to take the gain on the other [e.g. write a protected put, stock goes up, dump the put while holding the stock] - your loss should have been disallowed in the first year). My guess is the IRS in practice doesn't enforce the rules unless not obeying the straddle rules is reducing your taxes in the thousands or maybe even tens of thousands, meaning we're talking 5-6 figure capital gains on straddled positions (due to difficulty in applying the straddle rules). Perhaps it is this "materiality" that is leading to no one here worrying about this. Regardless, it is actually really hard to find a CPA knowledgable about these rules. The few I've talked either won't take my business or will charge in the thousands to do it [as they need to spend time learning]. I'm actually confident I understand the rules better than most [who never touch this stuff] -- my problems right now is in the reporting.
%% I agree with that about 95.777%; since the taxpayer is responsible to pay, not the CPA. BUT like a local banker/director said ''a good CPA will pay for himself in a minute'',