those that mentioned price discovery/liquidity etc are absolutely correct. without individual traders, there would be a monopoly for price discovery/liquidity etc. the average person does not understand how this would affect them, but i can assure you they wouldnt like it the average american praises capitalism, yet despises anyone who actually practices it this is because many of the opinions that many people say have everything to do with what the people around them say and approve of, whether it makes sense or not, or is even consistent.
I don't understand why you talk about "conspiracy theories" : what's that kind of argument it is ? I talk about specific facts only. If you are scared of facts exposed well it's not the fault of any theory . Some people in Finance are very smart it doesn't mean that all are smart and as I said Moral has nothing to do with Profits. If it is profitable to do illegal things rationality conducts with 100% probability some (of course not all) will do it. BCCI is not a MYTH since they have been closed officially by FBI but first they were very hard to close as Reagan or Bush I don't remember (I will check agin) didn't want any inquiry about BCCI, it's on the insistance of a congressman that the inquiry was finally conducted. And today the same persons of BCCI has moved to another structure Kalyle group. And guess what are Karlyle activities and who are those persons you should be surprised.
Is it a good question ? Why do people ask themselves those kind of question (I don't exclude myself ) : is it because they feel somehow guilty ? What does it change to know the answer ? I have always said to myself: thing is worth only if it doesn't stay in abstraction and makes you act. So I try to act. For those who gets an answer do you try to act also ?
Aside from the usual reasons: Providing liquidity, and such, if you really enjoy it and it makes you happy ..then that is your contrubution to society. You are one less miserable SOB that the world has to live with, to me that's a good thing. I worked at MER for 12years, and hated almost every minute of it, since I started trading 4 years ago I'm a much happier person for it. (More frustrated sometimes, are you listening Mr. Market!), but overall feel much better about myself. Also, if you consider that the median income in the US is about $34,000, then if you are successful at trading and make a good living, your taxes are able to pay for more firemen, policemen, teachers etc,as you pay an outsized share; also a good contribution. So stop worrying about or become a paramedic or something "useful"; my taxes will pay your salary!
Trading creates money out of thin air because of people trading in different time frames. While it may not do much for supply side economics it does much on the demand side. Trading creates a demand for goods and services. How many thousands of dollars are spent monthly by the people on this list buying services of others, buying books and tapes? How many jobs have been created by traders? How web sites make money off of traders? Traders certainly hold more noble positions in society as most government workers.
...that would have been nice. Except that in trading it's usually the other way around. The privilaged few have access to the best info and the best minds are working for them. Thus the wealth transfer is usually from the poor who predominantly are invested in mutual funds and dramatically underdiversified 401Ks to the ones who are already more than affluent... It is a comforting thought that you will be giving most of your profits to charities etc, but I don't think you can easily assume the money came from the filthy rich members of society. At least not predominantly