Subject: File No. 4-652
From: David Scales

September 28, 2012

Please include Nanex LLC into your roundtable. I'd imagine their experience in monitoring the state of high-frequency trading would be invaluable in having a balanced discussion.

I believe the SEC has a significant amount of catching up to do in regards to regulating the exchanges, dark pools, and internalizers. Europe and Australia have already made strides to maintain a reasonable market structure and I believe the SEC has the responsibility to do the same.

Thank you for giving me the opportunity to comment.

Best Regards,
David S.