Buying a rental property is just exiting the previous holder too.

I would define it differently. If you are putting money in something with the hope that the price goes up, that's speculating. If you put money in something with the hope that it generates income then that's investing.

So buying stocks could be either one.

> Buying a rental property is just exiting the previous holder too.

And using it to generate income, maintaining it for the customers (renters) etc