If you trade then you earned the income from the trading and owe tax on it, not your wife. Why even bother to do the whole marriage to a foreign spouse nonsense, why not just claim your Russian friend Boris did the trading so you're not responsible for the taxes, certainly the IRS has no authority over him? You can certainly lie to the IRS, you don't need to go to the effort of a foreign spouse to do that, and you may even get away with it. That doesn't make it legal and it sure as hell won't help you when the IRS figures out what you're doing. But don't pay any attention to me, go give it a try and let us all know how that works out for you.
If you don't grasp the difference between setting up a foreign corporation and getting married, you clearly haven't been part of a happy marriage, and yes, you've got the emotional maturity of a high schooler regardless of your actual age! Heck, my high schoolers have more emotional maturity than that.
Since you have deputized yourself as the emotional maturity police on my hypothetical example of a US citizen marrying a foreign national for tax purposes, I'll give you a couple of more examples that are a little more realistic so you can be even more judgmental....
*US citizen travels abroad, falls in love, gets married and finds there is a possible tax advantage of wife not adopting resident alien status or citizenship. - Go ahead discuss this with your 17 year old emotionally sophisticated, non- tax paying, sexting is acceptable focus group.
Another example to ponder....
*I trade with POA for a foreign entity (corporate or individual) who purchases a house in Bali that I have no-ownership of but I have the lifetime right to use. I use the house and allow friends and family to use the house. - Please have your high school barometers grade this one? And then see if they are intellectually developed enough to join this example with the example above and keep their black and white judgmental mindset.(http://www.ampclearing.com/pdf/POA.pdf)
Its my experience that most people who get all 'holier than though' on how others find ways to reduce their taxes do not earn enough to take advantage of the opportunities that are out there or are just envious, or both.
But on a serious note I am glad that you are such upstanding citizen, it balances out the degenerates like myself.