"Opportunity cost" is one of the difficult concepts that novice investors just have to learn on their own with experience. I learned about it when my money got locked up in CMM during the cease-trade order.
I've also learned to always have a big pile of money (20-50% depending on market cycle) in cash - you never know when some crazy short-term opportunity may come up that could net you a 10% profit over 1-2 days if only you had the dry powder. Cash is a money-making investment, in that it represents the opportunity for short-term returns. Again, that goes back to opportunity cost.
(Of course, if you have a big position in a stock that's significantly in the green since you bought it, that also represents a cash position, I think - as long as you're happy to sell some of it when an opportunity comes up.)
I've also learned to spread out my holdings among several stocks - this is mining, and every stock carries with it the possibility of a surprise pop. Or a surprise crash, of course. So you want to participate in a lot of plays - but not too much in any one.
Just look at PEZ - no reason to have been holding it this week since the buyout was already priced in, but if you were, your fine investment just lost you a bundle because Baja's governor just outlawed open-pit mining. Who woulda thought that would happen?
Anyway - all these are things that can't be learned except through painful experience. So there's really no point in me going on about them, except I want to kill time before I leave for work.
All I know is I'm up 55% on the year, and made money on my GNH play even though I didn't get in til 60 cents. If you bought GNH at .18 you should have no complaints... but to get in at .60 and do well, you've really got to shake your head.
