Nanex sells market data and tools for analyzing market data.
Historically (I haven't looked in a long time) their market data was inappropriate for HFT usages as it was not at the fidelity required for those applications, but it was very cheap in comparison to other market data providers.
This led to a natural segmentation of their market such that most of their clients are people who are a) interested in market structure but b) not interested in high fidelity market structure information and who aren't interested enough to spend more on other options. That frequently is large block traders (hedge funds) who have a natural opposition to HFT market makers.
Whether that is the only factor in their strident anti-HFT position or if they have other personal moral reasons for it as well, they also publish a highly biased blog railing against HFT, but that is not their business.
In the industry, I never encountered them in the context of "highly respected financial research firm" and only in the context of "dirt cheap market data archive".
I'd say "highly alarmist" based on what I've read from them over the years. They're pushing people to use their product, so it makes sense for them to publish alarmist stuff which segues into their product offerings.
I used to respect them -- they do (or perhaps did) visualize events of interest in the markets in a useful way.
Their recent crusading against HFT however has moved outside the bounds of logic, as evidenced by this "definition" of HFT, which is just silly (as others here have pointed out).
It's an excellent example of the middleman that only extracts money from a system, that adds no value to the system.
They insert themselves into the transactions where they can siphon off very small amounts of money over a very large number of transactions. Nobody benefits but them from what they're doing, no one walks away with something in their hands or brains by their actions.
The counter argument is that they do provide a benefit, by providing liquidity and/or making price discovery more efficient.
Whether it's "good" liquidity or not, and whether the discovered prices actually reflect true value or not, is a discussion that seems to fairly rapidly head down an acrimonious rathole.
I don't think it's acrimonious to say that no, that liquidity is not beneficial to society as a whole.
I struggle to see how any sector other than the financial sector would suffer if all trades happened once a second, or even once a minute. No process in the human world is going to change the value of a company quicker than that.
I tend to agree that the value of a company doesn't actually change substantially from one second to the next. But to focus on that is to ignore the value of having liquidity available. For an example of what can happen when there isn't enough liquidity, take a look at the graph of RSP on the morning of August 24th.
If traders, be they high-frequency or otherwise, can't make money by making liquidity available, they won't do it. Less liquidity means wider spreads, which means higher costs especially for smaller transactions (i.e. individual investors).
You could reasonably argue that HFT has caused expenses to increase for large investors who need to buy or sell large volumes of shares. But to the extent that is true, it is like saying that large investors used to get on average an unreasonably good deal at the expense of their counter parties. As in any free market, an especially good price for one party is by definition an especially bad price for the other party.
Look at a market without market-makers. Housing is a good one. Houses sell only when there are "slow" traders willing to buy and sell. Have you ever bought or sold a house? Would you like the financial markets to be more like real estate?
Be very clear what you mean when you say this. Because the vast majority of the time when people talk about HFT, the only way the "insert themselves" into transactions is by acting as the counter party to one side of the transaction.
In this context they add a lot of value to the system, they smooth the demand curves in time and take on some of the risks of warehousing supply.
The big claim with HFT is they "add liquidity", but there's evidence that shows the opposite. Indeed it seems like HFT's only add liquidity when it's already plentiful, but reduces liquidity when it's really needed.
I'm not sure who is making that claim, but I think what they are implying is that HFT "provides liquidity cheaper than the previous system of pit traders" or even "fragmentation of exchanges has dramatically brought down exchange fees at the cost of added complexity for liquidity providers (and possibly liquidity consumers). Only HFT systems could have cheaply dealt with this new complexity".
In any case, I'd sum it up as "it is cheaper to trade now after the rise of HFT than at any other time, at least some of that is because they can market make more efficiently than a dude in a vest". Vanguard for one agrees with me (http://www.cnbc.com/2014/04/25/vanguard-chief-defends-high-f...).
What many critics have claimed is that this has come at the cost of an increase in volatility, especially in the form of flash crashes and it is unclear as of yet if that is better/worse than the traditional liquidity crunches we saw under the previous regime and still see in markets not dominated by HFT.
The Fed was specifically talking about this in the context of treasury bond (and futures) volatility and a skeptic might wonder which is more likely to have caused volatility in the treasury markets, HFT or unprecedented fed monetary policy.
None of which is germane to the question of what the OP meant when he said that HFT insert themselves into transactions.
Also the waste of talent argument is a red herring. People who say that assume the alternative is no financial system in their heads. It takes many fewer people to run many HFT firms than to run one JPM prop trading floor which is the actual alternative.