I think what you have to do is enter a stock-trading business that has no income, and enter your trading expenses as business expenses. But the tax professional that you consult will be able to tell you exactly how to do it in a way that does not look like a money-losing business to the IRS.
You do not form an LLC.
You cannot deduct the full cost of the laptop unless you use it 100% exclusively for trading or recordkeeping for your trading, with no personal use at all. No personal email, no Facebook, no Skype, etc. The tax professional that you consult will be able to tell you how much you can deduct, and advise you whether to deduct it all in the year of purchase or depreciate it over a number of years.
