Dose the stock market reflect real investors(by 'real' I mean people looking at where the company will be in a few years and planning to hold an investment for

Dose the stock market reflect real investors(by 'real' I mean people looking at where the company will be in a few years and planning to hold an investment for that length of time)? I wonder how much of this is an institution selling enough shares to change a metric and trigger a bunch of algorithms.