Sec Form 4 Filing - ARCH Venture Partners VIII, LLC @ Twist Bioscience Corp - 2018-11-02

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 ARCH Venture Partners VIII, LLC 2. Issuer Name and Ticker or Trading Symbol Twist Bioscience Corp [ TWST] 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) 8755 WEST HIGGINS ROAD, SUITE 1025 3. Date of Earliest Transaction (MM/DD/YY) 11/02/2018 (Street) CHICAGO, IL60631 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 Common Stock 11/02/2018 C 1,182,645 A 1,182,645 I See footnote ( 2 ) ( 3 ) Common Stock 11/02/2018 C 718,275 A 1,900,920 I See footnote ( 2 ) ( 3 ) Common Stock 11/02/2018 C 266,776 A 2,167,696 I See footnote ( 2 ) ( 3 ) Common Stock 11/02/2018 C 224,726 A 2,392,422 I See footnote ( 2 ) ( 3 ) Common Stock 11/02/2018 P 15,000 ( 4 ) A $ 14 2,407,422 I See footnote ( 2 ) ( 3 ) Common Stock 11/02/2018 C 894,146 A 894,146 I See footnote ( 5 ) ( 3 ) Common Stock 11/02/2018 P 60,000 ( 4 ) A $ 14 954,146 I See footnote ( 5 ) ( 3 )

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 ) 11/02/2018 C 1,182,645 ( 1 ) ( 6 ) Common Stock 1,182,645 ( 1 ) 0 I See footnote ( 2 ) ( 3 ) Series B Preferred Stock ( 1 ) 11/02/2018 C 718,275 ( 1 ) ( 6 ) Common Stock 718,275 ( 1 ) 0 I See footnote ( 2 ) ( 3 ) Series C Preferred Stock ( 1 ) 11/02/2018 C 266,776 ( 1 ) ( 6 ) Common Stock 266,776 ( 1 ) 0 I See footnote ( 2 ) ( 3 ) Series D Preferred Stock ( 1 ) 11/02/2018 C 224,726 ( 1 ) ( 6 ) Common Stock 224,726 ( 1 ) 0 I See footnote ( 2 ) ( 3 ) Series D Preferred Stock ( 1 ) 11/02/2018 C 894,146 ( 1 ) ( 6 ) Common Stock 894,146 ( 1 ) 0 I See footnote ( 5 ) ( 3 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other ARCH Venture Partners VIII, LLC 8755 WEST HIGGINS ROAD SUITE 1025 CHICAGO, IL60631 X ARCH Venture Fund VII, L.P. 8755 WEST HIGGINS ROAD SUITE 1025 CHICAGO, IL60631 X ARCH Venture Fund VIII Overage, L.P. 8755 WEST HIGGINS ROAD SUITE 1025 CHICAGO, IL60631 X ARCH Venture Partners VII, L.P. 8755 WEST HIGGINS ROAD SUITE 1025 CHICAGO, IL60631 X ARCH Venture Partners VII, LLC 8755 WEST HIGGINS ROAD SUITE 1025 CHICAGO, IL60631 X BYBEE CLINTON 8755 WEST HIGGINS ROAD SUITE 1025 CHICAGO, IL60631 X NELSEN ROBERT 8755 WEST HIGGINS ROAD SUITE 1025 CHICAGO, IL60631 X Signatures /s/ Mark McDonnell, Attorney-in-Fact for Keith Crandell, Managing Director of ARCH Venture Partners VII, LLC, General Partner of ARCH Venture Partners VII, L.P., Genera l Partner of ARCH Venture Fund VII, L.P. 11/06/2018 Signature of Reporting Person Date /s/ Mark McDonnell, Attorney-in-Fact for Keith Crandell, Managing Director of ARCH Venture Partners VIII, LLC, General Partner of ARCH Venture Fund VIII Overage, L.P. 11/06/2018 Signature of Reporting Person Date /s/ Mark McDonnell, Attorney-in-Fact for Keith Crandell, Managing Director of ARCH Venture Partners VII, LLC, General Partner of ARCH Venture Partners VII, L.P. 11/06/2018 Signature of Reporting Person Date /s/ Mark McDonnell, Attorney-in-Fact for Keith Crandell, Managing Director of ARCH Venture Partners VII, LLC 11/06/2018 Signature of Reporting Person Date /s/ Mark McDonnell, Attorney-in-Fact for Keith Crandell, Managing Director of ARCH Venture Partners VIII, LLC 11/06/2018 Signature of Reporting Person Date /s/ Mark McDonnell, Attorney-in-Fact for Clinton Bybee 11/06/2018 Signature of Reporting Person Date /s/ Mark McDonnell, Attorney-in-Fact for Robert Nelsen 11/06/2018 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Upon closing of the Issuer's initial public offering, each share of preferred stock was automatically converted into one share of the Issuer's common stock, for no additional consideration, on a 1:1 basis. ( 2 )The shares are directly held by ARCH Venture Fund VII, L.P. ("ARCH Fund VII"). The sole general partner of ARCH Fund VII is ARCH Venture Partners VII, L.P. ("ARCH Partners VII"), which may be deemed to be the beneficial owner of the shares held by ARCH Fund VII. The sole general partner of ARCH Partners VII is ARCH Venture Partners VII, LLC ("ARCH VII LLC"), which may be deemed to be the beneficial owner of the shares held by ARCH Fund VII. ARCH Partners VII and ARCH VII LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. ( 3 )Clinton Bybee and Robert Nelsen are the managing directors of ARCH VII LLC and ARCH VIII LLC, and they may be deemed to beneficially own the shares held by ARCH Fund VII and ARCH Overage. Messrs. Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. ( 4 )Reflects shares purchased in the Issuer's initial public offering. ( 5 )The shares are directly held by ARCH Venture Fund VIII Overage, L.P. ("ARCH Overage"). The sole general partner of ARCH Overage is ARCH Venture Partners VIII, LLC ("AVP GPLLC"), which may be deemed to be the beneficial owner of the shares held by ARCH Overage. AVP GPLLC disclaims beneficial ownership of such shares, except to the extent of any pecuniary interest therein. ( 6 )The expiration date is not relevant to the conversion of these securities.

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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