I am about to open an account with Tradestation to access the US markets at far better rates than going thru ASB. Part of the process is filling out a US IRS W8-BEN form, and now i'm wondering how much tax the US govt is going to want to take from my profits if any. Anybody have a quick rundown of the tax situation?

I'm not a trader, more a buy and hold investor, but will be purchasing a few put options and the like to hedge against general market downturns. No company or trust structure in use, just doing everything in my own name at this stage.

Thanks in Advance.