SEC Form 4

FORM 4		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 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Andreessen Horowitz Fund I, L.P. (Last) (First) (Middle) 2865 SAND HILL ROAD, SUITE 101 (Street) MENLO PARK CA 94025 (City) (State) (Zip)	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)
	3. Date of Earliest Transaction (Month/Day/Year) 06/12/2019
	4. If Amendment, Date of Original Filed (Month/Day/Year)	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. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	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
Class A Common Stock	06/12/2019		C		6,441,419	A	$0(1)	6,441,419	I	By: AH Parallel Fund IV, L.P.(2)(3)
Class A Common Stock	06/12/2019		C		10,189,412	A	$0(1)	10,189,412	I	By: Andreessen Horowitz Fund I, L.P.(4)

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 (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	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 (Month/Day/Year)		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: 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
Class B Common Stock	(1)	06/12/2019		C			6,441,419	(1)	(1)	Class A Common Stock	6,441,419	$0(1)	11,651,555	I	By: AH Parallel Fund IV, L.P.(2)(3)
Class B Common Stock	(1)	06/12/2019		C			10,189,412	(1)	(1)	Class A Common Stock	10,189,412	$0(1)	38,197,948	I	By:Andreessen Horowitz Fund I, L.P.(4)

1. Name and Address of Reporting Person* Andreessen Horowitz Fund I, L.P. (Last) (First) (Middle) 2865 SAND HILL ROAD, SUITE 101 (Street) MENLO PARK CA 94025 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Andreessen Horowitz Fund I-A, L.P. (Last) (First) (Middle) 2865 SAND HILL ROAD, SUITE 101 (Street) MENLO PARK CA 94025 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Andreessen Horowitz Fund I-B, L.P. (Last) (First) (Middle) 2865 SAND HILL ROAD, SUITE 101 (Street) MENLO PARK CA 94025 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* AH Equity Partners I, L.L.C. (Last) (First) (Middle) 2865 SAND HILL ROAD, SUITE 101 (Street) MENLO PARK CA 94025 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Andreessen Marc L (Last) (First) (Middle) 2865 SAND HILL ROAD, SUITE 101 (Street) MENLO PARK CA 94025 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* HOROWITZ BENJAMIN A (Last) (First) (Middle) 2865 SAND HILL ROAD, SUITE 101 (Street) MENLO PARK CA 94025 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. Each share of Class B Common Stock is convertible without payment or consideration into one share of Class A Common Stock at the option of the holder and has no expiration date.

2. 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.

3. (Continued from Footnote 2) Each of the Reporting Persons 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.

4. 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. Each of the Reporting Persons 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.

Remarks:

This Form 4 is the first of two Form 4s filed relating to the same event. Combined, the two reports report the holdings for the following reporting persons: Andreessen Horowitz Fund I, L.P., AH Equity Partners I, L.L.C., AH Parallel Fund IV, L.P., AH Equity Partners IV (Parallel), L.L.C., Marc L. Andreessen, Ben Horowitz, Andreessen Horowitz Fund I-A, L.P., Andreessen Horowitz Fund I-B, L.P., AH Parallel Fund IV-A, L.P., AH Parallel Fund IV-B, L.P. and AH Parallel Fund IV-Q, L.P. This Form 4 has been split into two filings because there are more than 10 reporting persons in total, and the SEC's EDGAR filing system limits a single Form 4 to a maximum of 10 reporting persons.

	Andreessen Horowitz Fund I, L.P. Andreessen Horowitz Fund I-A, L.P. Andreessen Horowitz Fund I-B, L.P. By: AH Equity Partners I, L.L.C. Its: General Partner By: /s/ Scott Kupor Scott Kupor, Chief Operating Officer	06/14/2019
	AH Equity Partners I, L.L.C. By: /s/ Scott Kupor Scott Kupor, Chief Operating Officer	06/14/2019
	Marc Andreessen /s/ Scott Kupor Scott Kupor, attorney-in-fact of Marc Andreessen	06/14/2019
	Ben Horowitz /s/ Scott Kupor Scott Kupor, attorney-in-fact of Ben Horowitz	06/14/2019
	** Signature of Reporting Person	Date
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