It really doesn't matter where the money goes though. Even if an investor spends the money on golden bathtubs and private jets, the money is being spent in the economy. If they keep it in the bank it's getting leant out to small businesses.
The other issue is velocity. If loans last 10 years but it takes 1 year to find someone to lend the money to. Then effectively only 90% of the money is loaned out on average.
In practice you might well be right about velocity, but there is no "the money" of which 90% is lent out.
America & most other countries use fractional reserve banking. A pretty reasonable interpretation of this is that making a loan is nearly equivalent to creating the money needed to make the loan.
All the existing money that can be lent that exists is, in fact, currently lent out.
Also, banks may make loans, but they can also sell them to other groups without reserve requirements. Allowing for a near endless streams of new loans.
Thus the total amount of loans is not fixed and depends on where in the economy the actual currency is.
I am not an economist but I've been trying to learn a bit about it and a bit about financial management/investing. I'm currently at the velocity of money stage of my learning.
https://en.m.wikipedia.org/wiki/Velocity_of_money
It's not really the same thing as the trickle down that the parent poster mentioned. From what I can tell, you hit the nail on the head.
An influx of money will mean the money moves. Also, when money moves is when the government taxes it. So, the influx will increase the velocity of money and will have an effect on the economy.
That's not the same as the parent post implied, where there's a reduction in taxes and that is supposed to result in the money trickling down. That's not the same as an influx of money. One is people keeping their money, the second is people getting more money.
If I understand correctly, they are different things. Then again, I may not understand correctly. As I said, I am still learning.
Also, I've said this before and no one has given me a good answer yet. Corporations already have record amounts of cash on hand [1], but they're largely not doing anything with it. What reason do we have to believe that getting cash back on shore would change this behavior at all? After all, taxes are on profits - companies could effectively repatriate their money tax free today by spending it on hiring more people, building factories, etc.
[1] https://www.spglobal.com/our-insights/US-Corporate-Cash-Reac...
https://qz.com/1064061/house-flippers-triggered-the-us-housi...