Quote from HolyGrail:
Income from trading is not "passive income". Having money that is invested and maintained by another party IS passive income. The IRS defines passive income as indicated below.
1. Trade or busines activities that you DO NOT materially participate during the year.
2. Rental activities, even if you do materially participate unless you are a real estate professional.
Furthermore, if you actively have more than 500 hours in trading or any other pursuit in any calendar year then it cannot be reported as passive income.
http://www.irs.gov/pub/irs-pdf/p925.pdf