WORK Slack Technologies Inc

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 * Andreessen Marc L	2. Issuer Name and Ticker or Trading Symbol Slack Technologies, Inc. [ WORK ]	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) 2865 SAND HILL ROAD, SUITE 101	3. Date of Earliest Transaction (MM/DD/YYYY) 1/8/2020
(Street) MENLO PARK, CA 94025 (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
Class A Common Stock	1/8/2020		S		60536	D	$24.13 (1)	0	I	By AH Capital Management, L.L.C. (2)
Class A Common Stock								9814412	I	By Andreessen Horowitz Fund I, L.P. (3)(4)
Class A Common Stock								3816419	I	By AH Parallel Fund IV, L.P. (5)(6)
Class A Common Stock								1413143	I	By Trust (7)
Class A Common Stock								1693391	I	By Trust (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)	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.13 to $24.135. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
(2)	The shares are held of record by AH Capital Management, L.L.C. The members of AH Capital Management, L.L.C. are Marc Andreessen and Ben Horowitz, who share voting and dispositive power with respect to the shares held by AH Capital Management, L.L.C. Each of the Reporting Persons disclaims the existence of a "group" and disclaims beneficial ownership of these securities except to the extent of its pecuniary interest therein, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of the reported securities for purposes of Section 16 or for any other purpose.
(3)	These shares are held of record by Andreessen Horowitz Fund I, L.P., as nominee for Andreessen Horowitz Fund I, L.P., Andreessen Horowitz Fund I-A, L.P. and Andreessen Horowitz Fund I-B, L.P. (collectively, the "AH Fund I Entities"). AH Equity Partners I, L.L.C. ("AH EP I"), the general partner of the AH Fund I Entities, has sole voting and dispositive power with regard to the shares held by the AH Fund I Entities. The managing members of AH EP I are Marc Andreessen and Ben Horowitz. Marc Andreessen and Ben Horowitz share voting and dispositive power with respect to the shares held by the AH Fund I Entities.
(4)	(Continued from Footnote 3) Each of the Reporting Persons disclaims the existence of a "group" and disclaims beneficial ownership of the securities held by the AH Fund I Entities (and this report shall not be deemed an admission that any such person is the beneficial owner of such securities), except to the extent of its pecuniary interest, if any, in the securities by virtue of its interest in the AH Fund I Entities.
(5)	These shares are held of record by AH Parallel Fund IV, L.P., for itself and as nominee for AH Parallel Fund IV-A, L.P., AH Parallel Fund IV-B, L.P., and AH Parallel Fund IV-Q, L.P. (collectively the "AH Parallel Fund IV Entities"). AH Equity Partners IV (Parallel), L.L.C. ("AH EP IV Parallel"), the general partner of the AH Parallel Fund IV Entities, has sole voting and dispositive power with regard to the shares held by the AH Parallel Fund IV Entities. The managing members of AH EP IV Parallel are Marc Andreessen and Ben Horowitz. Marc Andreessen and Ben Horowitz share voting and dispositive power with respect to the shares held by the AH Parallel Fund IV Entities.
(6)	(Continued from Footnote 5) Each of the Reporting Persons disclaims the existence of a "group" and disclaims beneficial ownership of the securities held by the AH Parallel Fund IV Entities (and this report shall not be deemed an admission that any such person is the beneficial owner of such securities), except to the extent of its pecuniary interest, if any, in the securities by virtue of its interest in the AH Parallel Fund IV Entities.
(7)	The shares are held of record by the LAMA Community Trust of which Marc Andreessen and his spouse are trustees. Each of the Reporting Persons disclaims the existence of a "group" and, other than Marc Andreessen, disclaims beneficial ownership of these securities, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of the reported securities for purposes of Section 16 or for any other purpose.
(8)	The shares are held of record by a family trust for which Ben Horowitz is a trustee. Each of the Reporting Persons disclaims the existence of a "group" and, other than Ben Horowitz, disclaims beneficial ownership of these securities, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of the reported securities for purposes of Section 16 or for any other purpose.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Andreessen Marc L 2865 SAND HILL ROAD SUITE 101 MENLO PARK, CA 94025		X
HOROWITZ BENJAMIN A 2865 SAND HILL ROAD SUITE 101 MENLO PARK, CA 94025		X

Signatures
Marc Andreessen /s/ Scott Kupor Scott Kupor, attorney-in-fact of Marc Andreessen		1/10/2020
**Signature of Reporting Person		Date
Ben Horowitz /s/ Scott Kupor Scott Kupor, attorney-in-fact of Ben Horowitz		1/10/2020
**Signature of Reporting Person		Date