We could also take the route of the Federal Reserve purchasing up equities (The Bank Of Japan does this [1]), issuing deposit accounts to citizens directly (trivial for the Federal Reserve to support this [disclaimer: I work in the financial services industry, and feel qualified to make this statement]), and providing UBI to those accounts using the Federal Reserve as an intermediary/conduit (lookout Blackrock and Vanguard! there's a new index fund manager on the block!).
Voilà, Citizen's Dividend.
EDIT: The Federal Reserve operates independently of the US government, and does not require Congressional or Presidential approval to perform this "monetary policy". [2]
"Although an instrument of the U.S. Government, the Federal Reserve System considers itself "an independent central bank because its monetary policy decisions do not have to be approved by the President or anyone else in the executive or legislative branches of government, it does not receive funding appropriated by the Congress, and the terms of the members of the Board of Governors span multiple presidential and congressional terms."
[1] https://www.bloomberg.com/news/articles/2017-07-18/boj-s-etf...
Are you proposing their equity also be taxed "at rest"? How would that work?
Same way property is taxed. A taxing authority sends you a bill (based on duration of ownership), with the tax rate set by legislation. In this case, the custodian of your equity would send you your bill, with a copy sent to the IRS. I don't believe who accepts the payment needs to be defined at this time (although sending payments directly to the IRS or through your custodian are both trivial matters).
When you have trillions you just need a bigger mattress, like Ireland, for instance.