1) trading is not intellectually satisfying though the money is good for the effort put in.
2) i would not trade if i could earn money doing something else.
3) Trading is useless to society you neither providing a service or adding value to anything:there is no reason why market gives you money
WRONG WRONG WRONG.
1) I took my graduate academics from renowned scholars (much better teachers than their student). I sat in on every seminar, workshop, and paper presentation from other institutions (Ivys, Stanford, Michigan) that I could squeeze into. I packed my brain with (more than) it could hold. And I *still* find that trading, in general, demands *every* class and *every* bit of information that I've ever learned. And I STILL have to keep learning -- For 5 years, I was nearly 100% credit spreads. Right now (or, these last 6 months, I guess), I find myself retooling once again, into a long/short Index futures system.
If I had not brought my entire game to the market, I would have been bounced from trading many years ago. "Not satisfying"????? That's whacked.
2) Then I would caution you to do that 'something else' as soon as possible, because the market in which you trade *demands* your best thinking, and if you're not 100% on it? It will suck your milkshake dry.
3) If you are getting paid from trading, then you are either providing a service, or you are a thief. You are not a thief. You provide two services that 'society' finds worthy of compensation (even if indirectly). First is that you are a liquidity provider (or, a risk arbitrageur): when the market is $10 BID and $11 ASK, and you buy at $10.25 and sell at $10.75, you have provided an extra 25¢ to both sides of that market, and the market has paid you that middle 50¢ for making the transaction happen. ("Yay!" you.) But secondly, markets depend on information for sound allocation of societal resources. The prices at which everything trades is the signal that there is too much of things with declining prices, and too little of things with rising prices. YOUR TRADING is part-and-parcel of that information generation -- whether buying for investment, or selling for shorts: you are communicating to the entire rest-of-the-world, "Hey! Here's what I think of this good/service!" And the world listens, too.
Off of soapbox.
Huh. Ironchef and wrbtrader nailed it.

Could've saved myself some writing...

