Ok, that's interesting. I don't follow this: > What specific positions (or even total account value) I hold in my various accounts is not required for the IRS

Ok, that's interesting. I don't follow this: > What specific positions (or even total account value) I hold in my various accounts is not required for the IRS to compute my taxes. How can they compute your financial gains without knowing your portfolio changes? (sorry I'm not american and thus my preconceptions of how do you do taxes are weird for you).