As Rachel Maddow reported this night the financial aspect of the inquiry has ballooned. The target for the financial inquiry are Russian plutocrats who have laundered their money through Trump enterprises. As she reported the Wall Street Journal story that FinCen of Treasury the investigative arm into money laundering is to supply the Senate committee with documents which they claim" are necessary to prove whether there was collusion between Trump and associates and Russia."
Reuters printed a story that Russian plutocrats have bought millions of Trump properties through LLCs anonymously. Which is a prime way Russian launder money.
So wait for more from USA Today which catalogued all Trump properties and the units available for their project to get in full swing.
The point of following this money tail is to " ascertain whether these people had relations with the Russian government."
This is a lucrative field of endeavor and really shouldn't take that long.