Optimally its best to buy at rock bottom, but nobody knows where that is. We know for sure that everything (except for GM LOL) will more or less bounce back. So if I don't know where rock bottom is, I think the next best option is to buy before it hits rock bottom. Buying on the way up is bad i think.
This is what makes stock trading so exciting - everyone has their own way of thinking. I tend to be more comfortable buying stocks on the way up, and if they drop a bit, I'll top it up.
Re: penny stocks. Many stocks are up only on hype (TSX-V type), I've noticed that once BNN has some fancy analyst dude show up and tell everyone their top pick it tends to jump high the next day and then slowly go back to its place over a few weeks. I find them hard to valuate as well… but some sure give good returns.
all investing is is a type of arbitrage, and thats not gambling. theres an element of risk and potential of profit involved, but those are broad and dont qualify somthing as gambling.
most Christians I know, myself included, would say that science is the way through which we learn about everything that God has created, but we learn at the pace which he sets for us.