If you let your emotions control you, you'll get into a lot of trouble. For example, if you feel happy spending money on wants, if you let that happiness ruin you, you'll keep buying things. Similarly, if you are greedy and get overwhelmed by winnings or losses, you will now trade with larger lot sizes. I've read also in a book that we should act like machines or computers, where no emotions kick in, only algorithms, and find the best solutions to a particular situation. If we can really do that, we won't get into any trouble.
Compulsive stock market investment is now a new disease included in the DSM and henceforth we must make people who are prone to develop such compulsions aware of the same that this is a problem and they need to stop before they burn themselves out.
Point is that either type of compulsive actions are destructive, be it in gambling or trading or shopping or eating etc. However this compulsion comes as a counter mechanism to another obsession. Truly this revenge trading is a problem if someone is doing it regularly. Trading must be done with patience and research, waiting for the low price, pouncing on that and waiting till the high is reached to sell. Only then it an organized execution yielding the maximum possible profit.