What Motivates Us

According to numerous clinical studies, our number one fear in life is the fear of missing out. This is a stronger emotional trigger than the fear of losing.
This is a critically important behaviour for traders to be aware of because it explains why traders "buy at highs", "sell at lows" and "chase markets"
I can honestly say the times I have done all of the above, I have not thought through the details of the risk of the trade. Sure I may have had a vague understanding that risk was involved, but not to the degree of actually calculating a non-ambiguous risk level defining the maximum risk amount.
There are two outcomes here:

1. Without a clear line in the sand risk level, if the market moves against you very suddenly, you are not prepared to deal with cutting the trade. A fast market will move against you so quickly, that suddenly what was a paper profit is now a paper loss larger than your maximum tolerance. This creates the "deer in the headlights" response....and it only gets uglier from here....
2. If you do determine your risk level, you will quickly become aware that your risk to reward ratio is skewed, which should keep you out of the trade. This is not an easy task to achieve when trading intraday, as it is often the speed at which the market moves that has you reacting in the blink of an eye. However on the positive side, if you are on the sidelines, then you are in position to take advantage of these situations which catch traders out because you can take the other side of the trade.