The idea of making a living as a day trader appeals to a large number of people, but not everybody has a personality suitable for day trading. Even people that are successful in other fields (even related fields), often find that they are not compatible with day trading. Day trading is a flexible profession (meaning that it can be adapted to suit different styles), but there are a few qualities that all day traders need to have in their personalities, in order to be successful (profitable), and avoid becoming a nervous wreck in the process.
When non traders imagine day traders, many people think of traders in a trading pit, wearing brightly colored jackets, shouting and waving their arms about. While this may have been true once, it is no longer an accurate image of day trading. Modern day trading is performed by sitting quietly in front of a computer, waiting anywhere from a few minutes, to several hours, or even days, for the next trade to come along. Being able to wait patiently is a necessity, otherwise you will find yourself taking trades that are not part of your trading system (known as making up a trade), and most likely losing money on them. Waiting patiently does not necessarily mean doing nothing, and there are many things that you can do while you are waiting for your next trade. Some day traders join live trading rooms where they can interact with other traders, some traders play computer games and watch movies, and many day traders eat their meals while they are trading (breakfast often coincides nicely with the market open).
Deciding when to enter and exit trades is one of the most basic functions of a day trader, and it is important that these decisions are made as efficiently as possible. Being decisive is vital to successful day trading, otherwise you will only sit and watch trades that you should have actually taken. Being decisive does not mean being rash, and taking trades that you are not sure about, but it does mean acting promptly when a trade does come along. A common pitfall that many beginning day traders come across is seeing a trade occuring, but hesitating and waiting for the trade to start moving into profit before entering (waiting for confirmation that the trade is going to be a winning trade before they enter it). This always results in an entry price that is not as good as it would have been with a prompt entry, and can turn a winning trade into a losing trade.
Remaining calm during trading is one of the most important personality traits for a day trader, but it is also one of the most difficult to obtain and practice. As humans, the natural reactions to a winning trade are excitement and joy, and the natural reactions to a losing trade are panic and sadness, but day traders need to control these emotions, otherwise they will adversely affect their trading decisions (particularly the negative emotions). For example, the panic that occurs after a losing trade might make you take a new trade almost immediately in an attempt to make the money back, even though there was no trade according to your trading system.
Trading in Simulation
Trading in simulation is a good way to practice your patience, decisiveness, and calmness during trading, without risking any real money. After many hours, days, or weeks of simulation, you will have a good idea of how your personality and your emotions will affect your day trading, but even then, there will still be an emotional response when you start trading live.