That's what I'm saying. In the terminology of systems theory, the value of a stock over time tells you rather little about what's going on in the system compared to knowing both inflow and outflow.
True. There should be a simpler mechanism.
In case of stocks, there exists the balance sheet but there should be something simpler yet more informative. For instance, the regular watchlist we have (on Yahoo Finance) with a couple more datapoints from the balance sheet.
Note that I used the word "stock" in its system-theoretic meaning, i.e. an accumulating quantity whose level depends on inflow and outflow. Not in the financial equity sense.