Margin interest is treated as deduction to get to "NET" investment income or loss. if you have more than 3k of loss in one year, you can carryforward indefinetly meaning you can deduct next year and so on..If you hold your securities for more than a year , u will get favourable tax treatment but it all depends on you AGI, Adjusted Gross Income ...that's it for free tax advise..

What a week for my solar stocks....GO SOlAR...i love it..