If you carefully read what I wrote, you'll see I never said HFT is about liquidity and efficiency. I merely said HFT provides the market with the liquidity and efficiency. High frequency traders are motivated by money just like all market participants. People don't go to medical or law school to heal the sick or defend the innocent. They do it for the money, but that doesn't mean they don't occasionally heal or defend people.

High frequency trading is not like shooting fish in a barrel. Despite what the media would have you believe, trading of any sort is not easy, and HFT is no exception. High frequency traders are not out to get you. They're just out to make money in the market like all market participates. I'm convinced most of the media folks who bash HFT, really don't have a clue how HFT or the market works. They just think jumping on the HFT bashing bandwagon makes them sound smart. The unfortunate thing is their readers and viewers don't know how ignorant these commentators are and end up believing their nonsense.

Whether or not you want to admit it, financial markets are more liquid and efficient today than they've ever been, and HFT has a lot to do with it.

I encourage you to watch the video linked below to better understand HFT's effect on the market. Sosnoff knows his stuff.

https://www.tastytrade.com/tt/shows/weyg/episodes/130808_weyg

It really is unbelievable how much bad information people consume and believe concerning HFT. I challenge you to find one concrete instance where HTF has hurt you as a retail investor or trader.

HFT provides liquidity, and liquidity is of the utmost importance to traders.

HFT is very misunderstood by people who don't participate in or understand trading. HFT in fact adds tremendous value to all market participants by dramatically increasing market efficiency with the significant proportion of trading volume it's responsible for.

When you trade a security, there are actually two prices: the bid price and the ask price. When you buy, you pay the ask price; when you sell, you receive the bid price. The ask price is always higher than the bid price, with the market makers keeping the difference. This means that if you buy a stock and immediately sell it, you lose this difference--this is known as slippage. When there aren't many trades occurring, these prices widen out, and the high degree of slippage makes trading profitably much more difficult. With markets as efficient as they are now, which is largely due to HFT, these spreads are often a single penny wide. Before HFT, these spreads were often ten, twenty, or more times as wide.

Anytime you want to buy or sell something, it's highly desirable to have a line of people willing to make you an offer. High frequency traders are these people. It doesn't matter why they want to take the other side of your trade. All that matters is they are there enabling you to make trades more easily and at better prices.

Getting rid of HFT would be like going back to the dark ages when everyone was being ripped off by market makers.