These are "dark pools," of private electronic markets, mostly inthinly traded securities. The SEC wants to make sure that these have transparency and fair pricing, just like other types of transactions. And this is one instance where we think there is a good chance of the SEC's providing meaningful regulation.
Fair enough. But this regulatory action fits the agency's (previous, at least) "check list" approach to regulation.
On the other hand, we have previously observed, the SEC now appears to be more concerned about "trading" violations, rather than "lying" or disclosure violations. That's why it persecuted David Einhorn for moving the markets with his truthful, and highly resonant comments about Allied Capital, but did little follow up on Einhorn's allegations that Allied was creating the underlying problem by lying in the first place. It's like the school principal's view that the guy who fights back a bully is at least as guilty as the bully, for fighting.