Does money just grow on trees in the magic stock market? The amount of sustained non-bubble growth the stock market can generate is limited, not unbounded. It follows that if the HFT bots steals a slice of it, then the slice the regular gamblers get is smaller than it would otherwise have been.
They're already getting a slice. Look at any stock quote and notice that asks and bids are different amounts. That's where they get their money from: transactions, not growth. (Look up the expression "delta neutral".)
Is there a magic money tree? That involves a lot more economics classes than I took, so I won't even attempt to answer.
