FORM 3
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  Armstrong Stevan
2. Date of Event Requiring Statement (Month/Day/Year)
11/04/2011
3. Issuer Name and Ticker or Trading Symbol
CDSI HOLDINGS INC [CDSI]
(Last)
(First)
(Middle)
C/O SG BLOCKS, INC., 400 MADISON AVENUE, SUITE 16C
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
President, COO
5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

NEW YORK, NY 10017
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 Beneficially Owned
1.Title of Security
(Instr. 4)
2. Amount of Securities Beneficially Owned
(Instr. 4)
3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)
4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Common Stock 3,327,266
I (1)
By SMA Development Group LLC

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)
2. Date Exercisable and Expiration Date
(Month/Day/Year)
3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)
4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)
6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Armstrong Stevan
C/O SG BLOCKS, INC., 400 MADISON AVENUE
SUITE 16C
NEW YORK, NY 10017
  X     President, COO  

Signatures

Stevan Armstrong 11/07/2011
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(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).
(1) Such shares are held by SMA Development Group, LLC, an entity controlled by Mr. Armstrong. Mr. Armstrong specifically disclaims beneficial ownership of the shares of common stock held by SMA Development Group, LLC, except to the extent of his pecuniary interest therein, and this shall not be deemed to be an admission that Mr. Armstrong is the beneficial owner of such shares of common stock.

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