Firms with enough money to spend _can_ get a more accurate view of the market. The issue is proprietary data feeds. A trading platform is required to disseminate information to the consolidated tape at the same rate they do for a private feed, but that only holds for the "walls" of the trading platforms network. The consolidated tape is a LOT slower than a 100MB multicast feed being slurped up by a co-located server sitting 20 feet from the trading system.

If an HFT firm was "front running" as you put it, and you know about it, why doesn't the SEC? Front running is not legal. Or are you using the Flash Boys definition of front run which is "anyone that trades better than me" or "anytime I try to buy 50,000 shares but move the price"?

The SEC doesn't have infinite resources, but has to enforce somewhat selectively. It's possible that they disapprove of some kinds of HFT activities but doubt their own ability to persuade a jury sufficiently well to justify the cost of prosecution.

I don't mean this as a comment on HFT or the law, I really don't know. I'm just pointing out that the SEC is bound by budgetary constraints and that litigation is very expensive, so they have to do cost/benefit analysis and prioritize the cases that are more likely to win.

And this is before political considerations come into the picture. News articles described the 'resident's SEC pick as being more interested in capital formation than enforcement; that seems a pretty reasonable assessment to me, given that S&C was representing Goldman Sachs during the epic CDO litigation, the cabinet is stuffed with GS alumni, and the administration's general attitude seems to be less regulation for more muscular and dynamic capitalism.

http://www.reuters.com/article/us-usa-trump-sec-idUSKBN14N1Y...