Below is CME Group's notification to the CFTC that it is vastly expanding the markets that its privately held trading group, GFX, will trade in.
Employees of GFX may use Globex terminals or other electronic means to enter orders..
Shocking.
But it appears that GFX was already trading outside of currency products. From CME's 2009 10-K:
In the same 10-K, CME refers to GFX as "proprietary trading" and warns it could hide unauthorized activities:
And finally, a look at one of the currency futures (Euros) that GFX supposedly provides liquidity in, during an ECB news announcement:
Zooming in on the first 2 seconds of the drop - note the crazy wild price oscillations that take place in less than a tenth of a second!