I don't like to get into too much detail (see above disclaimer), but our traders, and all Professionals in a K-1 situation, do not have "capital gains" - are taxed on mark to market as ordinary income, and are completely exempt from Self Employment (FiCA) taxes. If you're getting a 1099, for some reason, as misc income, I assume you can file a Schedule C and expense normal business expenses.
1099-MISC
If you earned more than $600 from a person or company as a self-employed individual you will receive a 1099-MISC from the individual or company. You will receive a separate 1099-MISC for each independent job you had during the previous year. This income is generally reported on the Schedule C.
Once again, I left Public Accounting in 1975, LOL....I suggest you find a decent accountant. However, there are very few who really understand the K-1 Traders.
Good luck,
Don