The United States Statistical Release Z.1 now has a new look and more data. It now includes the Integrated Macroeconomic Accounts.
According to the Integrated Macroeconomic Accounts site (which was available separately but online only):
These tables present a sequence of accounts that relate production, income and spending, capital formation, financial transactions, and asset revaluations to changes in net worth between balance sheets for the major sectors of the U.S. economy. They are part of an interagency effort to further harmonize the BEA National Income and Product Accounts (NIPAs) and the Federal Reserve Board Financial Accounts of the United States (FAUS).
The structure of these tables is based on the internationally accepted set of guidelines for the compilation of national accounts that are offered in the System of National Accounts 2008 (SNA). The estimates that are currently displayed are based on the data that were available in the NIPAs and FAUS on September 21, 2017. See “Financial Accounts of the United States (Z.1)” for more information.
So now you can look at things such as households’ capital gains easily from the Z.1. Such as from the table below: