No. Price is purely the consequence of supply versus demand. As...

No. Price is purely the consequence of supply versus demand. As we know, both of these (especially demand) can fluctuate for a host of reasons, including (though not exclusively) factors related to crowd psychology. In brief, psychology dictates whether the crowd's focus is on long term factors (usually associated with anticipated business & economic performance) or short term factors (like fears of price falls, or excitement about possible corporate action, to give two examples).

Unless you believe a fair price fluctuates with whims of psychology, then it cannot be assumed that price is always fair.