EXHIBIT A

JOINT FILING AGREEMENT

The undersigned hereby agree that the statement on Schedule 13G with respect to the Common Stock of Armour Residential REIT, Inc. dated as of February 14, 2012 is, and any amendments thereto (including amendments on Schedule 13D) signed by each of the undersigned shall be, filed on behalf of each of us pursuant to and in accordance with the previsions of Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended.

Date: February 14, 2012	MAGNETAR FINANCIAL LLC
	By:	Magnetar Capital Partners LP, its Sole Member
	By:	/s/ Alec N. Litowitz
		Name:	Alec N. Litowitz
		Title:	Manager of Supernova Management LLC, the General Partner of Magnetar Capital Partners LP
Date: February 14, 2012	MAGNETAR CAPITAL PARTNERS LP
	By:	/s/ Alec N. Litowitz
		Name:	Alec N. Litowitz
		Title:	Manager of Supernova Management LLC, the General Partner of Magnetar Capital Partners LP
Date: February 14, 2012	SUPERNOVA MANAGEMENT LLC
	By:	/s/ Alec N. Litowitz
		Name:	Alec N. Litowitz
		Title:	Manager
Date: February 14, 2012	/s/ Alec N. Litowitz
	Alec N. Litowitz