All valuation has a degree of subjectivity as price really is set by buying pressure vs. selling pressure.  However if you are looking at Apple, larger profits and a new, growing market should mean the company truly is worth significantly more.  Is some of the $80 hype?  maybe.  But is that just a random bet that can move in either direction by a random amount based on unknown and unpredictable forces -- NFW?  This entire analogy of a casino strikes me as lame.

We already have strong incentives to hold shares 1 year or more.  Capital gains taxes are much lower than regular income from short term speculation.