I haven't seen much correlation between good trading and intelligence. Some outstanding traders are quite intelligent, but a few aren't. Many outstanding intelligent people are horrible traders. Average intelligence is enough. Beyond that, emotional makeup is more important.

If the losses don't hurt, your financial survival is tenuous.

You can be very promiscuous in your research, but not in your trading.

Large profits are even more insidious than large losses in terms of emotional destabilization. I think it's important not to be emotionally attached to large profits. I've certainly made some of my worst investments after long periods of winning.

I take the point of view that missing an important trade is a much more serious error than making a bad trade.

Investing is a negative game emotionally. If you're playing for the emotional satisfaction, you're bound to lose, because what feels good is often the wrong thing to do. When all the criteria are in balance, do the thing you least want to do.

Don't think about what the market's going to do; you have absolutely no control over that. Think about what you're going to do if it gets there.