A single member LLC that's a disregarded entity that only has a broker's account in it is not reported on a schedule c instead it's put on the schedule d as if the LLC was never created. Putting a broker's account in LLC is a waste of time. If the brokers account is in a multi-member LLC then you need to file a partnership return form 1065 however the nature of the income is still investment. Please seek out local professional advice so you can learn the federal and state rules that governs this kind of activity.
