SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13D/A

(Rule 13d-101)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO §240.13d-1(a) AND AMENDMENTS THERETO FILED

PURSUANT TO §240.13d-2(a).

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

FIRST SECURITY GROUP, INC.

(Name of Issuer)

Common Stock, Par Value $0.01

(Title of Class of Securities)

336312202

(CUSIP Number)

TIMOTHY E. LADIN

MFP INVESTORS LLC

667 MADISON AVENUE, 25TH FLOOR

NEW YORK, NEW YORK 10065

(212) 752-7345

(Name, Address and Telephone Number of Person

Authorized to Receive Notices of Communication)

October 31, 2015

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. ¨

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See §240.13d-7 for other parties to whom copies are to be sent.

(Continued on following pages)

(Page 1 of 7 Pages)

* The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP NO. 336312202

Schedule 13D

Page 2 of 7

1	NAMES OF REPORTING PERSONS
	MFP Partners, L.P.(1)

2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) ¨
				(b) ¨
3	SEC USE ONLY
4	SOURCE OF FUNDS
	WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
	TO ITEM 2(d) or 2(e)			¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION
	Delaware
NUMBER OF		7	SOLE VOTING POWER
SHARES			0
BENEFICIALLY		8	SHARED VOTING POWER
OWNED BY			0
EACH REPORT-		9	SOLE DISPOSITIVE POWER
ING			0
PERSON WITH		10	SHARED DISPOSITIVE POWER
			0
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
	0
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
	CERTAIN SHARES			¨
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
	0
14	TYPE OF REPORTING PERSON
	PN

	(1) MFP Investors LLC is the general partner of MFP Partners, L.P. (“MFP”). Michael F. Price is the managing partner of MFP and the managing member and controlling person of MFP Investors LLC.

CUSIP NO. 336312202

Schedule 13D

Page 3 of 7

1	NAMES OF REPORTING PERSONS
	MFP Investors LLC(1)

2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) ¨
				(b) ¨
3	SEC USE ONLY
4	SOURCE OF FUNDS
	AF
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
	TO ITEM 2(d) or 2(e)			¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION
	Delaware
NUMBER OF		7	SOLE VOTING POWER
SHARES			0
BENEFICIALLY		8	SHARED VOTING POWER
OWNED BY			0
EACH		9	SOLE DISPOSITIVE POWER
REPORTING			0
PERSON WITH		10	SHARED DISPOSITIVE POWER
			0
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
	0
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
	CERTAIN SHARES			¨
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
	0
14	TYPE OF REPORTING PERSON
	OO

	(1) MFP Investors LLC is the general partner of MFP Partners, L.P. (“MFP”). Michael F. Price is the managing partner of MFP and the managing member and controlling person of MFP Investors LLC.

CUSIP NO. 336312202

Schedule 13D

Page 4 of 7

1	NAMES OF REPORTING PERSONS
	Michael F. Price(1)

2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) ¨
				(b) ¨
3	SEC USE ONLY
4	SOURCE OF FUNDS
	AF
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
	TO ITEM 2(d) or 2(e)			¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION
	United States of America
NUMBER OF		7	SOLE VOTING POWER
SHARES			0
BENEFICIALLY		8	SHARED VOTING POWER
OWNED BY			0
EACH REPORT-		9	SOLE DISPOSITIVE POWER
ING			0
PERSON WITH		10	SHARED DISPOSITIVE POWER
			0
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
	0
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
	CERTAIN SHARES			¨
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)
	0
14	TYPE OF REPORTING PERSON
	IN

	(1) MFP Investors LLC is the general partner of MFP Partners, L.P. (“MFP”). Michael F. Price is the managing partner of MFP and the managing member and controlling person of MFP Investors LLC.

CUSIP NO. 336312202

Schedule 13D

Page 5 of 7

This Amendment No. 1 (this “Amendment”) amends the Schedule 13D (the “Schedule 13D”) filed on April 12, 2013 by MFP Partners, L.P., a Delaware limited partnership (“MFP”), MFP Investors LLC, a Delaware limited liability company and general partner of MFP and Mr. Michael F. Price, relating to the common stock, par value $0.01 (the “Common Stock”), of First Security Group, Inc., a Tennessee corporation (“FSGI” or the “Issuer”). Capitalized terms used herein but not otherwise defined shall have the meaning ascribed to them in the Schedule 13D. Except as specifically provided herein, this Amendment does not modify any of the information previously reported in the Schedule 13D. Information in respect of each Reporting Person is given solely by such Reporting Person and no Reporting Person has responsibility for the accuracy or completeness of information supplied by any other Reporting Person.

This Amendment No. 1 to Schedule 13D is the final amendment to the Schedule 13D and an exit filing for the Reporting Persons. Items 4, 5 and 7 of the filed the Schedule 13D are hereby amended as set forth below:

Item 4. Purpose of the Transaction

Item 4 of the Schedule 13D is hereby supplemented as follows:

Effective October 31, 2015 (the “Closing Date”), the Issuer merged with and into Atlantic Capital Bancshares, Inc. (“Atlantic Capital”) with Atlantic Capital continuing as the surviving corporation. The merger consideration paid to holders of the Issuer’s shares consisted of cash and Atlantic Capital common stock.

Item 5. Interest in Securities of the Issuer

Item 5 of the Schedule 13D is hereby supplemented as follows:

(a) As of the date of this Amendment to Schedule 13D, the Reporting Persons are no longer beneficial owners or no longer may be deemed to be beneficial owners (as the case may be), of any shares of Common Stock.

(b) As of the date of this Amendment to Schedule 13D, the Reporting Persons are no longer beneficial owners or no longer may be deemed to be beneficial owners (as the case may be), of any shares of the Common Stock.

(c) Transactions in the Common Stock during the past 60 days: As further described in Item 4, effective on the Closing Date, each share of Common Stock issued and outstanding immediately prior to the Closing Date, including the securities beneficially owned by the Reporting Persons was converted into the merger consideration.

(d) No person other than the Reporting Persons is known to have the right to receive, or the power to direct the receipt of, dividends from, or proceeds from the sale of, the shares of Common Stock reported in this Amendment to Schedule 13D.

(e) On October 31, 2015, the Reporting Persons ceased to beneficially own in excess of 5% of the Common Stock.

Item 7. Material To Be Filed as Exhibits

Exhibit 1

Joint Filing Agreement, dated as of April 12, 2013, by and among MFP Partners, L.P., MFP Investors LLC and Michael F. Price (incorporated by reference to Exhibit 1 to Schedule 13D, dated as of April 12, 2013, filed by the Reporting Persons)

CUSIP NO. 336312202

Schedule 13D

Page 6 of 7

SIGNATURE

After reasonable inquiry and to the best of our knowledge and belief, the undersigned certify that the information set forth in this statement is true, complete and correct.

Dated: November 3, 2015

	MFP Partners, L.P.,
	by its General Partner,
	MFP Investors LLC

	By:	/s/ Michael F. Price
	Name:	Michael F. Price
	Title:	Managing Partner


	MFP Investors LLC
	By:	/s/ Michael F. Price
	Name:	Michael F. Price
	Title:	Managing Member


	/s/ Michael F. Price
	Michael F. Price

CUSIP NO. 336312202

Schedule 13D

Page 7 of 7

INDEX OF EXHIBITS

Exhibit 1

FIRST SECURITY GROUP INC/TN SC 13D/A