I think that exits are the most important element in trading. It's all about exit strategy and risk management.
The MOST important element has not been mention in this thread. That's why there are so many lossers in this game.
I loved most of the voted answers .. they're wrong! Nearest thing to 'right' is Market Selection. The most important element: you have to research, learn and know your market. Who actually looks at the data of a market and even begins to ask the logical questions they need answered? And your asking goes on being refined as you go along researching and test trading. This is a professional and institutional approach.
No, the voting is correct. How many times have you been right and still lost money? Psychology and money management are way more important than the market you trade. If you have those mastered, market selection is irrelevant.
When the numbers are starring you in the face, you will know it. And then you come back to a thread like this or the thousands of like it on ET, and realize that your arm is as important as your leg, and your eyes as important as your nose, etc. Being profitable requires enormous work to hone your craft or system, and the markets love to probe for weakness no matter what it is. That's why no finite list of "good qualities" will ever encompass what is required. Most of the answers given here are looking at it the "problem" upside down. When the problem is turned right side up, all the holes get filled naturally, with the exception of possibly Money Management, or how to change bet size based on edge. That is still an unsolved problem for me because I still don't understand how to extract a probability of success for a given trade from my systems. That probably means fixed fraction as a short term solution, but I am not sure... nitro
The most important element of trading is Self Control Self Control - to maintain discipline Self Control - to only take the right setups Self Control - to let profits run Self Control - to cut losses Self Control - to plan a trade Self Control - to trade a plan Self Control - to use proper money management Self Control - to control yourself - Self Control