Under the Securities Exchange Act of 1934

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications)

(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. o

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

* 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).

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Item 1.           Security and Issuer.

This Schedule 13D relates to shares of the Common Stock, $0.01 par value per share (“Common Stock”) of Xencor, Inc., a Delaware corporation (the “Issuer” or “Xencor”).  The principal executive offices of the Issuer are located at 111 West Lemon Avenue, 2nd Floor, Monrovia, CA 91016.

Item 2.           Identity and Background.

(a)         This Schedule 13D is being filed by John S. Stafford III (the “Reporting Person”).

(b)         The residence address for the Reporting Person is 1854 N. Maud Avenue, Chicago, IL 60614.

(c)          The Reporting Person is employed as Chief Executive Officer and President of Ronin Capital, LLC located at 350 North Orleans Street, Suite 2N, Chicago, IL 60654.

(d)         During the past five years, the Reporting Person has not been convicted in any criminal proceeding (excluding traffic violations and similar misdemeanors).

(e)          During the past five years, the Reporting Person has not been a party to any civil proceeding of a judicial or administrative body of competent jurisdiction which resulted in any judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violations with respect to such laws.

(f)           The Reporting Person is a United States citizen.

Item 3. Source and Amount of Funds or Other Consideration.

All purchases of Common Stock of the Issuer made by the Reporting Person were made using personal funds.  No funds were borrowed from any source to acquire the shares.

Item 4.                                 Purpose of Transaction.

All Xencor shares owned by the Reporting Person have been acquired for investment purposes.  The Reporting Person may purchase additional securities of the Issuer from time to time in open market or private transactions.  In addition, the Reporting Person may dispose of all or a portion of the securities of the Issuer at any time.  The Reporting Person reserves the right to increase or decrease his holdings on such terms and at such times as he may decide.

Other than as described above in this Item 4, the Reporting Person does not have any plan or proposal relating to or that would result in:  (a) the acquisition by any person of additional securities of the Issuer or the disposition of securities of the Issuer; (b) an extraordinary corporate transaction, such as a merger, reorganization or liquidation, involving the Issuer or any of its subsidiaries; (c) a sale or transfer of a material amount of assets of the Issuer or any of its subsidiaries; (d) any change in the present board of directors or management of the Issuer, including any plans or proposals to change the number or terms of directors or to fill any existing vacancies on the board; (e) any material change in the present capitalization or dividend policy of the Issuer; (f) any other material change in the Issuer’s business or corporate structure including but not limited to, if the issuer is a registered closed-end investment company, any plans or proposals to make any changes in its investment policy for which a vote is required by Section 13 of the Investment Company Act of 1940; (g) any changes in the Issuer’s charter, by-laws or instruments corresponding thereto or other actions which may impede the acquisition of control of the Issuer by any person; (h) causing a class of securities of the Issuer to be delisted from a national securities exchange or to cease to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association; (i) a class of equity securities of the Issuer becoming eligible for termination of registration pursuant to Section 12(g)(4) of the Exchange Act; or (j) any action similar to those enumerated above.

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Item 5.           Interest in Securities of the Issuer.

The following information with respect to the ownership of the Common Stock of the Issuer by the Reporting Person filing this Schedule 13D is provided as of December 6, 2013:

(a)         The Reporting Person beneficially owns 7,841,203 shares of the Common Stock of the Issuer, or approximately 25% of the Issuer’s outstanding Common Stock.  This amount includes 282,572 shares of the Issuer’s Common Stock held by Drogheda, LLC.

(b)         The Reporting Person has sole power to vote and dispose of the securities of the Issuer held by it.

(c)          The Reporting Person has not effected any other transactions in the Issuer’s Common Stock within the past sixty days, except as provided herein.

(d)         Not applicable.

(e)          Not applicable.

Item 6.           Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer.

None.

Item 7.           Material to Be Filed as Exhibits.

None.

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Signature

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

The original statement shall be signed by each person on whose behalf the statement is filed or his authorized representative. If the statement is signed on behalf of a person by his authorized representative (other than an executive officer or general partner of the filing person), evidence of the representative’s authority to sign on behalf of such person shall be filed with the statement:  provided, however, that a power of attorney for this purpose which is already on file with the Commission may be incorporated by reference. The name and any title of each person who signs the statement shall be typed or printed beneath his signature.

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