I'd like to summarize my view on trading and discuss it with more experienced traders. 1) The nature of markets Dynamic, non-linear process. That's why there's no Holly Grail, no single formula which explains market's swings. There are many ways, methods to profitable trading. We can't say that one indicator/system/style is better than the other. Most of the time, predictions about the future probably have 50/50 chance to be successful. But there're few moments when predictions can have an edge above 50%. 2) Systematic vs discretionary trading Since markets are non-linear, trading systems will fail. Every system must experience a huge drawdown in the future. Optimization won't help, because markets change. Diversifying over a range of different systems and markets may be a good idea. Trading systems may not react in timely manner to fundamental news or events - they can appear suddenly and can have large influence on markets. Discretionary trading can be more flexible and ( who knows? ) more profitable. 3) Money management Probably the fundamental thing in trading. After 50% loss, you must earn 100% to go flat. Math will never change, so proper money management is the key to profitability and can save you from bankruptcy. 4) Luck Luck has some impact on trader's profit or losses. We can't calculate it, only estimate it. One thing is for sure: the more trades are made, the less significant luck factor is. Markets have to be non-linear in order to exist. Trading is more an art than science ( now I agree with you, ChrisM! ). That's all. Comments appreciated!