Sec Form 4 Filing - AH Parallel Fund IV, L.P. @ Slack Technologies, Inc. - 2019-06-07

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

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1. Name and Address of Reporting Person AH Parallel Fund IV, L.P. 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/YY) 06/07/2019 (Street) MENLO PARK, CA94025 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ 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 Series A Preferred Stock ( 1 ) 06/07/2019 C 13,164,690 ( 1 ) ( 1 ) Class B Common Stock ( 2 ) 13,164,690 $ 0 0 I By: Andreessen Horowitz Fund I, L.P. ( 3 ) Series B Preferred Stock ( 1 ) 06/07/2019 C 35,222,670 ( 1 ) ( 1 ) Class B Common Stock ( 2 ) 35,222,670 $ 0 0 I By: Andreessen Horowitz Fund I, L.P. ( 3 ) Series C Preferred Stock ( 1 ) 06/07/2019 C 10,481,400 ( 1 ) ( 1 ) Class B Common Stock ( 2 ) 10,481,400 $ 0 0 I By: AH Parallel Fund IV, L.P. ( 4 ) ( 5 ) Series D Preferred Stock ( 1 ) 06/07/2019 C 5,490,180 ( 1 ) ( 1 ) Class B Common Stock ( 2 ) 5,490,180 $ 0 0 I By: AH Parallel Fund IV, L.P. ( 4 ) ( 5 ) Series D-1 Preferred Stock ( 1 ) 06/07/2019 C 35,190 ( 1 ) ( 1 ) Class B Common Stock ( 2 ) 35,190 $ 0 0 I By: a16z Seed-III, LLC ( 6 ) ( 7 ) Series E Preferred Stock ( 1 ) 06/07/2019 C 97,103 ( 1 ) ( 1 ) Class B Common Stock ( 2 ) 97,103 $ 0 0 I By: AH Parallel Fund IV, L.P. ( 4 ) ( 5 ) Class B Common Stock ( 2 ) 06/07/2019 J( 1 ) 48,387,360 ( 2 ) ( 2 ) Class A Common Stock 48,387,360 $ 0 48,387,360 I By:Andreessen Horowitz Fund I, L.P. ( 3 ) Class B Common Stock ( 2 ) 06/07/2019 J( 1 ) 16,068,683 ( 2 ) ( 2 ) Class A Common Stock 16,068,683 $ 0 18,092,974 I By: AH Parallel Fund IV, L.P. ( 4 ) ( 5 ) Class B Common Stock ( 2 ) 06/07/2019 J( 1 ) 35,190 ( 2 ) ( 2 ) Class A Common Stock 35,190 $ 0 42,990 I By: a16z Seed-III, LLC ( 6 ) ( 7 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other AH Parallel Fund IV, L.P. 2865 SAND HILL ROAD, SUITE 101 MENLO PARK, CA94025 X AH Parallel Fund IV-A, L.P. 2865 SAND HILL ROAD, SUITE 101 MENLO PARK, CA94025 X AH Parallel Fund IV-B, L.P. 2865 SAND HILL ROAD, SUITE 101 MENLO PARK, CA94025 X AH Parallel Fund IV-Q, L.P. 2865 SAND HILL ROAD, SUITE 101 MENLO PARK, CA94025 X AH Equity Partners IV (Parallel), L.L.C. 2865 SAND HILL ROAD, SUITE 101 MENLO PARK, CA94025 X Signatures AH Parallel Fund IV, L.P.AH Parallel Fund IV-A, L.P.AH Parallel Fund IV-B, L.P.AH Parallel Fund IV-Q, L.P.By: AH Equity Partners IV (Parallel), L.L.C.Its: General PartnerBy: /s/ Scott KuporScott Kupor, Chief Operating Officer 06/07/2019 Signature of Reporting Person Date AH Equity Partners IV (Parallel), L.L.C.By: /s/ Scott KuporScott Kupor, Chief Operating Officer 06/07/2019 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The Series A, Series B, Series C, Series D, Series D-1, and Series E Preferred Stock are each convertible into Class B Common Stock on a 1:1 basis and have no expiration date. Upon the effectiveness of the Issuer's Registration Statement on Form S-1, all shares of preferred stock will be converted, in an exempt transaction pursuant to Rule 16b-7, into shares of Class B Common Stock of the Issuer. ( 2 )Each share of Class B Common Stock is convertible into one share of Class A Common Stock at the option of the Reporting Person and has no expiration date. ( 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. Such persons and entities disclaim 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 his pecuniary interest, if any, in the securities by virtue of his interest in the AH Fund I Entities. ( 4 )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. ( 5 )(Continued from Footnote 4) Such persons and entities disclaim 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 his pecuniary interest, if any, in the securities by virtue of his interest in the AH Parallel Fund IV Entities. ( 6 )These shares are held of record by a16z Seed III, LLC ("a16z Seed"). The shares held directly by a16z Seed are indirectly held by Andreessen Horowitz Fund III, L.P., Andreessen Horowitz Fund III-A, L.P., Andreessen Horowitz Fund III-B, L.P., and Andreessen Horowitz Fund III-Q, L.P. (collectively, the "AH Fund III Entities"), the members of a16z Seed. AH Equity Partners III, L.L.C. ("AH EP III"), the general partner of the AH Fund III Entities, has sole voting and dispositive power with regard to the shares held by a16z Seed. The managing members of AH EP III are Marc Andreessen and Ben Horowitz. Marc Andreessen and Ben Horowitz share voting and dispositive power with respect to the shares held by a16z Seed. ( 7 )(Continued from Footnote 6) Such persons and entities disclaim beneficial ownership of the securities held by a16z Seed 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 his pecuniary interest, if any, in the securities by virtue of his interest in a16z Seed.

Remarks: This Form 4 is the second of three Form 4s filed relating to the same event. Combined, the three 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., AH Parallel Fund IV-Q, L.P., a16z Seed III, LLC, Andreessen Horowitz Fund III, L.P., Andreessen Horowitz Fund III-A, L.P., Andreessen Horowitz Fund III-B, L.P., Andreessen Horowitz Fund III-Q, L.P. and AH Equity Partners III, L.L.C. This Form 4 has been split into three 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.

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).

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