FORM 4
[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).         
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES
                                                                                  
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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
                      

1. Name and Address of Reporting Person *

Singer Eric 		2. Issuer Name and Ticker or Trading Symbol

QUANTUM CORP /DE/ [ QTM ] 		5. Relationship of Reporting Person(s) to Issuer (Check all applicable)

__ X __ Director                      __ X __ 10% Owner
_____ Officer (give title below)      _____ Other (specify below)
(Last)          (First)          (Middle)

825 THIRD AVENUE, 33RD FLOOR 		3. Date of Earliest Transaction (MM/DD/YYYY)

12/1/2017
(Street)

NEW YORK, NY 10022
(City)        (State)        (Zip)
4. If Amendment, Date Original Filed (MM/DD/YYYY)

 
6. Individual or Joint/Group Filing (Check Applicable Line)

___ Form filed by One Reporting Person
_ X _ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3) 		2. Trans. Date 2A. Deemed Execution Date, if any 3. Trans. Code
(Instr. 8) 		4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5) 		5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4) 		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V Amount (A) or (D) Price
Common Stock   (1) (2) 12/1/2017     A    16681   (3) A $0.00   16681   (4) (5) D    
Common Stock   (1) (2)                925983   (4) I   By: VIEX Opportunities Fund, LP - Series One   (6)
Common Stock   (1) (2)                176648   (4) I   By: VIEX Opportunities Fund, LP - Series Two   (7)
Common Stock   (1) (2)                2588833   (4) I   By: VIEX Special Opportunities Fund III, LP   (8)

Table II - Derivative Securities Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security
(Instr. 3) 		2. Conversion or Exercise Price of Derivative Security 3. Trans. Date 3A. Deemed Execution Date, if any 4. Trans. Code
(Instr. 8) 		5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5) 		6. Date Exercisable and Expiration Date 7. Title and Amount of Securities Underlying Derivative Security
(Instr. 3 and 4) 		8. Price of Derivative Security
(Instr. 5) 		9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Explanation of Responses:
(1)  This Form 4 is filed jointly by VIEX Opportunities Fund, LP - Series One ("Series One"), a series of VIEX Opportunities Fund, LP ("VIEX Opportunities"), a series limited partnership, VIEX Opportunities Fund, LP - Series Two ("Series Two"), a series of VIEX Opportunities, VIEX Special Opportunities Fund III, LP ("VSO III"), VIEX GP, LLC ("VIEX GP"), VIEX Special Opportunities GP III, LLC ("VSO GP III"), VIEX Capital Advisors, LLC ("VIEX Capital"), and Eric Singer (collectively, the "Reporting Persons").
(2)  The Reporting Persons are filing this report because each of the Reporting Persons is a member of a Section 13(d) group, disclosed in a Schedule 13D filed on behalf of the Reporting Persons, as it may be amended, which beneficially owns in the aggregate more than 10% of the Issuer's outstanding shares of Common Stock. Each Reporting Person disclaims beneficial ownership of the shares of Common Stock reported herein except to the extent of his or its pecuniary interest therein, and this report shall not be deemed to be an admission that any Reporting Person is the beneficial owner of such shares of Common Stock for purposes of Section 16 or for any other purpose.
(3)  Restricted stock units will fully vest on the earlier to occur of: i) the date of Quantum Corporation's next Annual Stockholder Meeting; and ii) September 1, 2018.
(4)  Reflects a 1-for-8 reverse stock split of the Issuer's common stock effected on April 18, 2017.
(5)  Mr. Singer, as the managing member of VIEX GP and VIEX Capital, may be deemed the beneficial owner of the (i) 925,983 Shares owned by Series One, (ii) 176,648 Shares owned by Series Two and (iii) 2,588,833 owned by VSO III.
(6)  Shares of Common Stock beneficially owned directly by Series One. VIEX GP, as the general partner of Series One, may be deemed the beneficial owner of the shares of Common Stock beneficially owned by Series One. VIEX Capital, as the investment manager of Series One, may be deemed the beneficial owner of the shares of Common Stock beneficially owned by Series One. Mr. Singer, as the managing member of each of VIEX GP and VIEX Capital, may be deemed the beneficial owner of the shares of Common Stock beneficially owned by Series One.
(7)  Shares of Common Stock beneficially owned directly by Series Two. VIEX GP, as the general partner of Series Two, may be deemed the beneficial owner of the shares of Common Stock beneficially owned by Series Two. VIEX Capital, as the investment manager of Series Two, may be deemed the beneficial owner of the shares of Common Stock beneficially owned by Series Two. Mr. Singer, as the managing member of each of VIEX GP and VIEX Capital, may be deemed the beneficial owner of the shares of Common Stock beneficially owned by Series Two.
(8)  Shares of Common Stock beneficially owned directly by VSO III. VSO GP III, as the general partner of VSO III, may be deemed the beneficial owner of the shares of Common Stock beneficially owned by VSO III. VIEX Capital, as the investment manager of VSO III, may be deemed the beneficial owner of the shares of Common Stock beneficially owned by VSO III. Mr. Singer, as the managing member of each of VSO GP III and VIEX Capital, may be deemed the beneficial owner of the shares of Common Stock beneficially owned by VSO III.

Reporting Owners
Reporting Owner Name / Address
Relationships
Director 10% Owner Officer Other
Singer Eric
825 THIRD AVENUE
33RD FLOOR
NEW YORK, NY 10022 		X X

VIEX Opportunities Fund, LP Series One
825 THIRD AVENUE
33RD FLOOR
NEW YORK, NY 10022
X

VIEX Opportunities Fund, LP Series Two
825 THIRD AVENUE
33RD FLOOR
NEW YORK, NY 10022
X

VIEX Special Opportunities Fund III, LP
825 THIRD AVENUE
33RD FLOOR
NEW YORK, NY 10022
X

VIEX Special Opportunities GP III, LLC
825 THIRD AVENUE
33RD FLOOR
NEW YORK, NY 10022
X

VIEX GP, LLC
825 THIRD AVENUE
33RD FLOOR
NEW YORK, NY 10022
X

VIEX Capital Advisors, LLC
825 THIRD AVENUE
33RD FLOOR
NEW YORK, NY 10022
X


Signatures
*/s/ Astrid Becker-Celik, Attorney in Fact for Eric Singer 12/4/2017
** Signature of Reporting Person Date

VIEX Opportunities Fund, LP - Series One; By: VIEX GP, LLC; its general partner; By: /s/ *, Managing Member 12/4/2017
** Signature of Reporting Person Date

VIEX Opportunities Fund, LP - Series Two; By: VIEX GP, LLC; its general partner; By: /s/ *, Managing Member 12/4/2017
** Signature of Reporting Person Date

VIEX Special Opportunities Fund III, LP; By: VIEX Special Opportunities GP III, LLC; its general partner; By: /s/ *, Managing Member 12/4/2017
** Signature of Reporting Person Date

VIEX Special Opportunities GP III, LLC; By /s/ *, Managing Member 12/4/2017
** Signature of Reporting Person Date

VIEX GP, LLC; By: /s/ *, Managing Member 12/4/2017
** Signature of Reporting Person Date

VIEX Capital Advisors, LLC; By /s/ *, Managing Member 12/4/2017
** Signature of Reporting Person Date


Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.