I think it was the infamous 1986 tax law that clearly prohibited the deduction of a personal computer to manage your investments or to do work at home.

However, the restrictions do not apply if the computer is used in a home business (even if it's a part time business) and if the home office is the only business location. In addition, you can deduct the cost of a computer that you use to manage your investments, but it's not a straight-forward procedure.

Instead of deducting the cost when you buy the computer, you can deduct it when you sell it or scrap it. But, you first have to elect to depreciate the computer on a straight line basis over 12 years. You then claim that on your tax return on schedule E and/or schedule A. As a practical matter, you won't get very much of a deduction each year. But, here's the trick. You do get to deduct the un-depreciated cost of the computer when you sell it or scrap it.

For most people, that's about two or three years after the purchase date. Thus, your deduction isn't eliminated. It's delayed.

Please note that unless the computer is used exclusively to manage your investments or for tax related matters, you must allocate the use between the investment and personal use. If you use the computer 50% of the time for investment and tax purposes, then you can deduct 50% of the cost as described above.