Sec Form 4 Filing - Dialectic Technology SPV LLC @ QUANTUM CORP /DE/ - 2025-12-18

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 Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person Dialectic Technology SPV LLC 2. Issuer Name and Ticker or Trading Symbol QUANTUM CORP /DE/ [ QMCO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 119 ROWAYTON AVENUE 3. Date of Earliest Transaction (MM/DD/YY) 12/18/2025 (Street) NORWALK, CT06853 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction 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

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction 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 (MM/DD/YY) 7. Title and Amount of Underlying Securities (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 Convertible Notes ( 1 ) ( 2 ) 12/18/2025 J 12/18/2025 ( 1 )( 2 ) Common Stock ( 1 ) ( 2 ) ( 1 ) ( 2 ) $ 54,718,114 ( 1 ) ( 2 ) D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Dialectic Technology SPV LLC 119 ROWAYTON AVENUE NORWALK, CT06853 X Signatures /s/ Dialectic Technology SPV LLC, by John Fichthorn, Authorized Signatory 12/23/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )On December 18, 2025 (the "Closing Date"), the Issuer issued senior secured convertible notes (the "Convertible Notes") in the aggregate principal amount of $54,718,114 to Dialectic Technology SPV LLC ("Dialectic"). The Convertible Notes mature December 18, 2028 (the "Maturity Date") and have an interest rate of 10.00% per annum, payable in kind, compounded annually. The initial conversion price of the Convertible Notes equals $10.00 per share (the "Conversion Price") of Common Stock, subject to adjustment, and includes antidilution protections in favor of Dialectic as set forth in the Convertible Notes. The Conversion Price is subject to adjustment on the last day of the three calendar quarters immediately following the Closing Date (each, a "Reset Price Date") to the greater of (a) $4.00 per share and (b) the lesser of (i) the then Conversion Price and (ii) the 30-day daily VWAP of the Common Stock immediately preceding the Reset Price Date. ( 2 )Based on the Conversion Price as of the Closing Date, the Convertible Notes were convertible into 5,471,811 shares of Common Stock. At the Issuer's option, all outstanding principal amount, accrued and unpaid interest and premium, if any, of any Convertible Notes outstanding on the Maturity Date will be exchanged into shares of Common Stock at an exchange price equal to 80% of the market price as set forth in the Convertible Notes. Following the six-month anniversary of Closing Date, if certain conditions are met, the Issuer may elect to require the exchange of a portion of the total outstanding amount of any Convertible Notes into shares of Common Stock at the then outstanding Conversion Price.

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 Number.