Sec Form 4 Filing - GILLIS STEVEN @ Pulmatrix, Inc. - 2018-04-03

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 GILLIS STEVEN 2. Issuer Name and Ticker or Trading Symbol Pulmatrix, Inc. [ PULM] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 8755 W HIGGINS, SUITE 1025, 3. Date of Earliest Transaction (MM/DD/YY) 04/03/2018 (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 04/03/2018 P 1,150,000 A 3,436,456 I See Footnotes ( 2 ) ( 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 Warrant (right to buy) $ 0.65 04/03/2018 P 1,150,000 04/03/2018 10/03/2018 Common Stock 1,150,000 ( 1 ) 1,150,000 I See Footnotes ( 2 ) ( 3 ) Series B Warrant (right to buy) $ 0.75 04/03/2018 P 1,150,000 04/03/2018 04/03/2023 Common Stock 1,150,000 ( 1 ) 1,150,000 I See Footnotes ( 2 ) ( 3 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other GILLIS STEVEN 8755 W HIGGINS, SUITE 1025 CHICAGO, IL60631 X Arch Venture Fund VII LP 8755 W HIGGINS, SUITE 1025 CHICAGO, IL60631 Former 10% owner ARCH Venture Partners VII, L.P. 8755 W. HIGGINS ROAD SUITE 1025 CHICAGO, IL60631 Former 10% owner ARCH Venture Partners VII, LLC 8755 W. HIGGINS ROAD SUITE 1025 CHICAGO, IL60631 Former 10% owner CRANDELL KEITH C/O ARCH VENTURE FUND VII 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO, IL60631 Former 10% owner BYBEE CLINTON C/O ARCH VENTURE FUND VII 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO, IL60631 Former 10% owner NELSEN ROBERT C/O ARCH VENTURE FUND VII 8755 WEST HIGGINS ROAD, SUITE 1025 CHICAGO, IL60631 Former 10% owner Signatures /s/ Steve Gillis 04/05/2018 Signature of Reporting Person Date /s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director of the general partner of the general partner of ARCH Venture Fund VII, L.P. 04/05/2018 Signature of Reporting Person Date /s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director of the general partner of ARCH Venture Partners VII, L.P. 04/05/2018 Signature of Reporting Person Date /s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell, Managing Director of ARCH Venture Partners VII, LLC 04/05/2018 Signature of Reporting Person Date /s/ Mark McDonnell, as Attorney-in-Fact for Keith Crandell 04/05/2018 Signature of Reporting Person Date /s/ Mark McDonnell, as Attorney-in-Fact for Clinton Bybee 04/05/2018 Signature of Reporting Person Date /s/ Mark McDonnell, as Attorney-in-Fact for Robert Nelsen 04/05/2018 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The reported securities were included within 1,150,000 Units purchased by ARCH Venture Fund VII, L.P. ("ARCH VII") for $0.65 per Unit. Each Unit consisted of one share of common stock, one Series A Warrant to purchase one share of common stock at an exercise price of $0.65 per share, and one Series B Warrant to purchase one share of common stock at an exercise price of $0.75 per share. ( 2 )Securities held of record byARCH VII. The sole general partner of ARCH VII is ARCH Venture Partners VII, L.P. ("ARCH Partners VII"), which may be deemed to have shared voting and investment power over the shares held by ARCH VII. The sole general partner of ARCH Partners VII is ARCH Venture Partners VII, LLC ("ARCH VII LLC"), which may be deemed to have shared voting and investment power over the shares held by ARCH VII. ARCH Partners VII and ARCH VII LLC disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. ( 3 )The managing directors of ARCH VII LLC are Keith Crandell, Clinton Bybee and Robert Nelsen and they may be deemed to have shared voting and investment power over the shares held by ARCH VII. Dr. Steve Gillis owns an interest in ARCH Partners VII, but does not have dispositive or voting power. Messrs. Crandell, Bybee and Nelsen and Dr. Gillis disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein.

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