or - maybe - better said --- the buying and selling is based on an expected future earnings --- amount and when
the PPS - plus or minus greed or fear is all done by 10000 models that estimate earnings per year - out say 10 years for a company and then the stream of earnings is discounted to the present. Fancy name is NPS of future earnings
YES - that is what drives price For example a growth company might be valued at earnings per year of 2 4 9 19 ----- so what if the expectations change due to earnings and management guidance to 2 4 5 8 ---- wow that stock will take a hit