It reflects people's perception of reality.
How exactly would you design a meter of actual reality, in the sense of where capital value is going to go in [delta-time]?
It's how everything always works. If you perceive that you have cancer, based on doctors' gathered and interpreted data, you will act on that perception.
With that attitude, sure.
There are real, objectively measurable signals that could be used to help moderate a purely perception-based market. But the “pure” “free” market system of US-style ultracapitalism doesn’t allow for that.
The scare quotes are because it’s not really a pure free market, it’s biased in favor of those who are most able to manipulate perception, and in general towards those who have the most paper wealth, which is not real economic value but rather based on those manipulated perceptions.
In other words, it’s a vicious cycle that pumps up valuations to continually move the market further and further away from any kind of reality. It’s a big part of why we see enormous boom-bubble-bust cycles.
Musk would be a good example: there’s no sane way to connect the actual economic value his companies have ever produced, or are ever likely to produce, to the market value that makes up his net worth.
The idea that “that’s as close as we can get” is basically a version of the Simpson’s quote, “We’ve tried nothing and we’re all out of ideas.”
There’s plenty of existing work that focuses on these issues. Just one example is C.H. Douglas’ “Social Credit”: https://en.wikipedia.org/wiki/Social_credit, which is a good starting pointing for thinking more seriously about the subject.
Those are merely your perception of "facts". And, surprise!, you are not the first person to ever determine there are "real, objectively measurable signals that could be used to help moderate". There's an entire legion of workers out there trying to do that.
If you genuinely perceived "real" indicators the market was overlooking, you should implement them and become a billionaire. Go ahead.