RMG Networks Holding (RMGN) SC 13D/A SCG Financial Acquisition / Wilson Donald R. Jr. ownership change

Exhibit 99.8

JOINT FILING AGREEMENT

The undersigned hereby agree that this Statement on Schedule 13D with respect to the shares of common stock of SCG Financial Acquisition Corp., dated the date hereof, is, and any amendments thereto signed by the undersigned shall be, filed on behalf of each of the undersigned pursuant to and in accordance with the provisions of Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended.  This Agreement may be executed in any number of counterparts, each of which shall be deemed an original and all of which together constitute one instrument.

IN WITNESS WHEREOF, the undersigned hereby execute this Agreement as of this 14th day of January, 2013

2012 DOOH INVESTMENTS LLC

By: DOOH Investment Manager LLC

Its: Manager

By:  /s/ Donald R. Wilson, Jr.                                           

Name:  Donald R. Wilson, Jr.

Title:  Manager

DOOH INVESTMENT MANAGER LLC

By:  /s/ Donald R. Wilson, Jr.                                           

Name:  Donald R. Wilson, Jr.

Title:  Manager

DRW COMMODITIES, LLC

By:  /s/ Donald R. Wilson, Jr.                                           

Name:  Donald R. Wilson, Jr.

Title:  Manager

DRW HOLDINGS, LLC

By:  /s/ Donald R. Wilson, Jr.                                           

Name:  Donald R. Wilson, Jr.

Title:  Manager

/s/ Donald R. Wilson, Jr.                                                      

Donald R. Wilson, Jr.