A lot has been written about the pros and cons of the SEC's new rules regarding short-selling. However, perhaps even more significant--but widely overlooked--is the fact that on Wednesday, the SEC approved the changes with a 3-2 vote. 

This is a big deal, folks. Christopher Cox, SEC chairman during President Bush's second term, was widely criticized for his policy that the regulator only passes new rules unanimously. His goal was to avoid partisan votes, since commissioners are typically chosen based on party affiliation. However, keep in mind that there cannot be more than three commissioners from the president's party.

Now that the SEC has brought the hammer down on flash-traders, it's angling to get rid of dark pools, which are very close cousins to the flash trade.  I believe someone writing on this very site a couple of months ago predicted this eventuality.

Flash-trading is the practice of buying early access to market prices, and the ability to trade on that information ahead of everyone else.   Dark pools are similar in that they allow big-volume traders to do business without publicly displaying prices until after a trade is executed.  This gives a built-in advantage to players who can afford to buy into dark pools (Goldman Sachs, for instance, is what you could call a charter member).