The stock market is a rich man's game. The rich can use financial trading to anonymize themselves, so they don't get hung for their crimes. And the rich can manipulate the market itself, driving stock values up by buying, driving them down by selling. Not to say all the insider trading dirty money can buy.

Anyone who's not ultra-wealthy will most likely get fleeced, because every stock they have will be devalued by wealthy investors dumping it, and every stock they buy will be less valuable than the one a wealthy investor decides to pump. Every action on the stock market feeds your money toward richer people than you, and never vice versa.