Holding company shares does nothing. Those shares are used as a medium of exchange with people actually doing some productive investment elsewhere.
The investment happens when somebody sells you the shares in exchange for fiat used to pay off the workers. Who do you buy your shares from? That's where you invest.
As for the first part, holding fiat or assets convertible to fiat when fiat has been issued with interest and must be eventually repaid under threat of confiscation of assets. :shrug: It's basically a game of chicken.
The investment happens when somebody sells you the shares in exchange for fiat used to pay off the workers. Who do you buy your shares from? That's where you invest.
As for the first part, holding fiat or assets convertible to fiat when fiat has been issued with interest and must be eventually repaid under threat of confiscation of assets. :shrug: It's basically a game of chicken.