If HFT is making it such that those with
faster computers are better able to shave a few
pennies of profit a
trade, off thousands of
trades per day, they are taking some of that potential profit away from the other less equipped short term traders.
The need for speed is the main reason you can't effectively start day
trading with simply the extra $ 5,000 in your bank account — online brokers do not have systems quite as
fast to service the true day trader, so literally the difference of
pennies per share can make the difference between a profitable and losing
trade.