The only reason you should really mess with forming an S-corp or LLC (which can be single member depending on the state of incorporation) is to establish a pension plan. If you are serious about trading for a living (and you are making money), you should establish a pension plan immediately. In addition to the ability to sock away 40K for yourself (and an additional 40k for your spouse assuming she works with you), you also have the ability to grow that money tax deferred, trading it yourself. Uncle sam can't touch it and neither can you. So without your uncle draining off 40% each year and without letting yourself buy a new SUV with it each year the money grow exponentially. I have only been trading for 6 years and I've had a pension plan for 5. I have 5 times more equity in my pension now. Oh if you do start an S-Corp and a self directed pension it makes sense to pay top dollar to a top notch law firm to start and maintain both. You don't want to go pinching pennies here, especially when an audit could cost you millions down the road (pension could be disqualified, etc.). You want your corp and your pension to be professionally managed and bullet proof to the IRS.