Good that you start your own thread as this is a question with lots of answers. I'd use ecomomy approach to your question.
Lets see, Genting touch and stay around RM10 before May 1993, Feb-Dec 1998 and Oct 2000 to Oct 2000.
As of RM20, Genting reach that points and stay above in between Dec 1994 and 1996 and again surpass the RM20 two years ago.
RM25 is it's highest points reach in May 1995 and again beginning of last year.
In stock market, the underlying economic issues/news pertaining a counter could let you estimate the support line for the next increase. TA could utilised for the calculation. At RM20, your friend say it's high because Genting is trading at it's high PE without any good supporting investment announcement.
When singapore announced the 2nd casino had been won by Genting, the supportline was reviewed to above RM30. That means, any price below that price is consider good buy.
Then came the news of Genting entry to Macau gaming market due to the deal with Stanley Ho. The support immediately went few ringgit up to RM33-34.
In fact, you have to rely on potential investment opportunities along with TA and some smart calculation to identify those 'undervalued' stocks.
PS. I used the round figure of RM10, RM20, RM30 just for illustration. The real supportline might not appear to be exactly that number.
