Perhaps spreads will increase -- but that 'extra cost' seems pretty trivial: Stock trading worked just fine when those spreads were larger. The average citizen isn't reaping the benefits of lower spreads, perhaps financial firms are, perhaps corporations are?
I'd say the larger disservice of HFT is funneling resources away from anything with real concrete meaning into this strange invented money-shuffling game in the financial world. A big drain on the potential of society's best and brightest is that many are drawn to chase money in silicon valley or in the financial world. And both options often serve to create a sort of technological bubble in which the idea of increasing 'real human value' can be lost.
Stock trading did not work just fine when those spreads were larger. Investors wound up paying substantial amounts of money to human specialists. In the same sense as most investors with basic sophistication would avoid mutual funds with management fees today, the large-spread stock markets of the 20th century basically imposed a similar fee structure on everyone just to be in the market at all. Not only that, but those fees were the product of overt collusion, as the "odd eighths" scandal illustrates.
No, no, no. Large spreads are terrible for normal investors.
It is nice to have a commercially viable use for compelling technology that is separate from the military-industrial complex though. Even well funded development stage pharmaceutical companies can have a hard time investing in speculative ideas on the hardware/software front.
Lower spreads on the underlying transactions of mutual funds leads to lower fees in the funds that make up the 401(k) plans used by the average citizen.
The invention of the atomic bomb has stopped superpowers armed to the teeth with conventional weapons from fighting each other in massive land wars every 10-20 years.
I'd say the larger disservice of HFT is funneling resources away from anything with real concrete meaning into this strange invented money-shuffling game in the financial world. A big drain on the potential of society's best and brightest is that many are drawn to chase money in silicon valley or in the financial world. And both options often serve to create a sort of technological bubble in which the idea of increasing 'real human value' can be lost.