I have no problem with HFT, but only because it is turning machines into things that are doing what humans did before, only at a speed that we can't keep up with as humans with our inherently physical interfaces. How is HFT different than traditional arbitrage except for the fact that it is faster and potentially at a scale that normal traders would never be able to keep up with? How is buying something one second an…
The HFT algos siphon off billions every year from the big, slow "dumb money" large institutional investors (e.g. pension funds, index funds, insurance companies).
For example, if an insurance company needs to liquidate its portfolio to pay a claim, the HFT will sense the insurance company placing an order in the market and try to skim 5-10 cents per share by manipulating the share price during the trade. Its a zero-sum game.
The insurance company lost and the algo won. Market markets exist to provide liquidity (match buyers and sellers), not to front-run and bid up orders from customers.