Ok - what complicated tradeoff do we make for things to count as "not rigged"? Please be specific.

Firstly, I wasn't arguing that the market is rigged: I was arguing that your argument doesn't hold, because there is actually an infinite amount of options to choose from, instead of just two (or one, as you are implying).

Secondly, you are not being constructive in your questioning, as you have already marked any answer I would give as 'complicated' (as if the system isn't complicated already).

Thirdly you are unfairly asking for 'specifics', where you yourself are arguing in generalities. Why won't you be specific: explain why the market is not rigged? 'The market' is not 'innocent until proven guilty' or 'efficient until proven otherwise'. You claim the market is fair: prove it. Please be specific.

Fourthly, as long as you are asking: I think we don't need the amount of Availability the system currently has. Quote stuffing is currently possible and you can get rid of that by reducing the availability of the system. Any form of rate limiting is a deliberate sacrifice of availability to achieve some other goal. Rate limiting the number of orders per licensed party, per instrument, per unit of time is eminently doable.

In conclusion, from the whole of your posts here on HN, I think you are way too infatuated with capitalism and unable to see her for the bitch she sometimes is. Your response was uncivil and uncalled for.

I didn't mean to imply there were only two possibilities. I merely wanted to ask what "not rigged" means to you? As the current article shows, there are real technical details necessary to figure out and the CAP theorem limits what can be done. It isn't a simple question to answer, and I personally lean towards "the SEC did a generally good job".

I don't know why you feel I was "uncivil" - I merely asked a question. However, please accept my apologies.

If you want to see assorted defenses of specific aspects of HFT, I have quite a few on my blog. I just posted a new one today. If you look way back, you'll also find a tutorial explaining the basic mechanics of HFT. I'm planning to publish an explanation of "quote stuffing" (aka screwups in your algorithm) shortly, as well as a takedown of Mark Cuban's idiotic article on the topic.

http://www.chrisstucchio.com/blog/tags/high%20frequency%20tr...

Don't sell privileged access to the stock exchange and don't enable abuse of the trading system.

Can you tell us what you mean technically by "privileged" access? Is there a threshold in dollars you have in mind for what is an acceptable fee for connectivity, or is it something else?

Is it a matter of the stock exchanges profiting from this, or the fact that it's possible at all?

I can't see how it can ever be possible to give everyone the same information at the same time. Latency will always be there, and renting rack space in a building near to the exchange will allow the information to reach you before the opposite coast of the country. Although this might mean that the owner of the neighboring building is the one making money, and not the stock exchange itself.