[jganetsk]

There is something called fund flow: https://www.investopedia.com/terms/f/fund-flow.asp

If a company issues $1000 of new stock, then that's an inflow of $1000 into the company. And if it buys back $1000 of stock, that's an outflow.

This kind of analysis is commonly applied to ETFs, for example, because ETFs will manage their outstanding shares by the issuance/redemption of creation units. https://www.investopedia.com/terms/c/creationunit.asp

You can certainly apply this analysis in aggregate, and you can also compute the net flow. I don't know if that's what the article posted here is doing.

Also, people talk about monetary policy as driving this, and that's wrong. Fiscal policy drives this (we've had a lot of new government debt issued in the last few years). Even though it's orthodox economics to attribute this to monetary policy, it's flat out wrong. Monetary policy does not impact net assets of the private sector. It's neutral in that regard. Fiscal policy definitely impacts net assets of the private sector. If you want to learn more, you can read "Where Do Profits Come From?" https://www.levyforecast.com/assets/Profits.pdf