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ahpau_sc13g.txt

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                               (Amendment No.   )*


                 Avista Healthcare Public Acquisition Corp.
                                (Name of Issuer)

                      Class A Ordinary Shares, par value $0.0001 per share
                          (Title of Class of Securities)

                                    G0726L125*
                                 (CUSIP Number)

                                December 31, 2016
             (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

[X] Rule 13d-1(b)

[ ] Rule 13d-1(c)

[ ] Rule 13d-1(d)

  *The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

** The Class A Ordinary Shares have no CUSIP number. The CINS number for the
Class A Ordinary Shares is G0726L125.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).

Page 1 of 8 Pages




CUSIP No. G0726L125                  13G                  Page 2 of 8 Pages
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     (1)    NAMES OF REPORTING PERSONS

            Hudson Bay Capital Management, L.P.

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     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                               (a)  [ ]
                                                               (b)  [ ]
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     (3)    SEC USE ONLY
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     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION

            Delaware
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NUMBER OF      (5)   SOLE VOTING POWER
                     0
SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)   SHARED VOTING POWER
                     3,000,000 Class A Ordinary Shares


OWNED BY       --------------------------------------------------------------

EACH           (7)   SOLE DISPOSITIVE POWER
                     0
REPORTING      --------------------------------------------------------------

PERSON WITH:   (8)   SHARED DISPOSITIVE POWER
                     3,000,000 Class A Ordinary Shares


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     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
            3,000,000 Class A Ordinary Shares

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     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                          [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            9.68%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON
            PN
-----------------------------------------------------------------------------






CUSIP No. G0726L125                  13G                 Page 3 of 8 Pages
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     (1)    NAMES OF REPORTING PERSONS

            Sander Gerber
-----------------------------------------------------------------------------
     (2)    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                               (a)  [ ]
                                                               (b)  [ ]
-----------------------------------------------------------------------------
     (3)    SEC USE ONLY
-----------------------------------------------------------------------------
     (4)    CITIZENSHIP OR PLACE OF ORGANIZATION
            United States
-----------------------------------------------------------------------------
NUMBER OF      (5)   SOLE VOTING POWER
                     0
SHARES         --------------------------------------------------------------

BENEFICIALLY   (6)   SHARED VOTING POWER
                     3,000,000 Class A Ordinary Shares


OWNED BY       --------------------------------------------------------------

EACH           (7)   SOLE DISPOSITIVE POWER
                     0
REPORTING      --------------------------------------------------------------

PERSON WITH:   (8)   SHARED DISPOSITIVE POWER
                     3,000,000 Class A Ordinary Shares


-----------------------------------------------------------------------------
     (9)    AGGREGATE AMOUNT BENEFICIALLY OWNED
            BY EACH REPORTING PERSON
            3,000,000 Class A Ordinary Shares


-----------------------------------------------------------------------------
     (10)   CHECK BOX IF THE AGGREGATE AMOUNT
            IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                          [ ]
-----------------------------------------------------------------------------
     (11)   PERCENT OF CLASS REPRESENTED
            BY AMOUNT IN ROW (9)
            9.68%
-----------------------------------------------------------------------------
     (12)   TYPE OF REPORTING PERSON
            IN
-----------------------------------------------------------------------------







CUSIP No. G0726L125                  13G                 Page 4 of 8 Pages
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Item 1.

(a)   Name of Issuer

           Avista Healthcare Public Acquisition Corp., a Cayman Islands
exempted company (the "Company")

(b)   Address of Issuer's Principal Executive Offices

           	65 East 55th Street, 18th Floor
		New York, New York 10022


Item 2(a).  Name of Person Filing

 This statement is filed by Hudson Bay Capital Management, L.P. (the
"Investment Manager") and Mr. Sander Gerber ("Mr. Gerber"), who are
collectively referred to herein as "Reporting Persons."

Item 2(b).  Address of Principal Business Office or, if none, Residence

The address of the principal business office of each of the Reporting
Persons is:

      777 Third Avenue, 30th Floor
      New York, NY 10017

Item 2(c).  Citizenship

Citizenship is set forth in Row (4) of the cover page for each
Reporting Person hereto and is incorporated herein by reference for each
such Reporting Person.

Item 2(d)   Title of Class of Securities

class A Ordinary Shares, par value $0.0001 per share (the "Class A
Ordinary Shares")


Item 2(e)   CUSIP Number

      	The Class A Ordinary Shares have no CUSIP number. The CINS number for
the Class A Ordinary Shares is G0726L125.
CUSIP No. G0726L125                  13G                   Page 5 of 8 Pages
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Item 3.     If this statement is filed pursuant to ss.240.13d-1(b) or
240.13d-2(b) or (c), check whether the person filing is a:

(a) [ ]   Broker or dealer registered under Section 15 of the Act (15 U.S.C.
          78o).

(b) [ ]   Bank as defined in Section 3(a)(6) of the Act (15 U.S.C. 78c).

(c) [ ]   Insurance company as defined in Section 3(a)(19) of the Act (15
          U.S.C. 78c).

(d) [ ]   Investment company registered under Section 8 of the Investment
          Company Act of 1940 (15 U.S.C. 80a-8).

(e) [X]   An investment adviser in accordance with ss.240.13d-1(b)(1)(ii)(E);

(f) [ ]   An employee benefit plan or endowment fund in accordance with
          ss.240.13d-1(b)(1)(ii)(F);

(g) [X]   A parent holding company or control person in accordance with
          ss.240.13d-1(b)(1)(ii)(G);

(h) [ ]   A savings association as defined in Section 3(b) of the Federal
          Deposit Insurance Act (12 U.S.C. 1813);

(i) [ ]   A church plan that is excluded from the definition of an investment
          company under Section 3(c)(14) of the Investment Company Act of
          1940 (15 U.S.C. 80a-3);

(j) [ ]   A non-U.S. institution in accordance with Rule 240.13d-1(b)(1)(ii)(J);

(k) [ ]   Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

If filing as a non-U.S. institution in accordance with 240.13d-1(b)(1)(ii)(J),
please specify the type of institution: ____




Item 4.     Ownership



	The information required by Items 4(a) - (c) is set forth in Rows (5)-
(11) of the cover page for each Reporting Person hereto and is incorporated
herein by reference for each such Reporting Person.

The percentage used in this Schedule 13G is calculated based upon an aggregate
of 31,000,000 Class A Ordinary Shares issued and outstanding, which is the sum
of (i) 30,000,000 Class A Ordinary Shares outstanding as of November 17, 2016,
as reported in the Company's Quarterly Report on Form 10-Q for the quarterly
period ended on September 30, 2016, filed with the Securities and Exchange
Commission on November 18, 2016 and (ii) the 1,000,000 Class A Ordinary Shares
issued by the Company on November 28, 2016 as reported in the Company's Current
Report on Form 8-K filed with the Securities and Exchange Commission on
November 28, 2016..

The Investment Manager, which serves as the investment manager to Hudson Bay
Master Fund Ltd., in whose name the securities reported herein are held, may
be deemed to be the beneficial owner of all Class A Ordinary Shares held by
Hudson Bay Master Fund Ltd.  Mr. Gerber serves as the managing member of Hudson
Bay Capital GP LLC, which is the general partner of the Investment Manager.
Mr. Gerber disclaims beneficial ownership of these securities.

Item 5.     Ownership of Five Percent or Less of a Class

      Not applicable.

Item 6.     Ownership of More than Five Percent on Behalf of Another Person

      See Item 4.

Item  7.    Identification and Classification of the Subsidiary Which Acquired
            the Security Being Reported on by the Parent Holding Company

      Not applicable.

Item 8.     Identification and Classification of Members of the Group

      Not applicable.

Item 9.     Notice of Dissolution of Group

      Not applicable.



CUSIP No. G0726L125                  13G                   Page 6 of 8 Pages
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Item 10.    Certification

By signing below each Reporting Person certifies that, to the best of his or
its knowledge and belief, the securities referred to above were acquired and
are held in the ordinary course of business and were not acquired and are not
held for the purpose of or with the effect of changing or influencing the
control of the issuer of the securities and were not acquired and are not held
in connection with or as a participant in any transaction having that purpose
or effect.







CUSIP No. G0726L125                   13G                  Page 7 of 8 Pages
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SIGNATURES

After reasonable inquiry and to the best of its knowledge and belief,
each of the undersigned certifies that the information with respect to it set
forth in this statement is true, complete, and correct.

Dated: January 30, 2017


HUDSON BAY CAPITAL MANAGEMENT, L.P.

By: /s/ Sander Gerber
Name:	Sander Gerber
Title: Authorized Signatory





/s/ Sander Gerber
SANDER GERBER



CUSIP No. G0726L125                   13G                  Page 8 of 8 Pages
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EXHIBIT I

                             JOINT FILING AGREEMENT

the undersigned acknowledge and agree that the foregoing statement on
Schedule 13G is filed on behalf of each of the undersigned and that all
subsequent amendments to this statement on Schedule 13G shall be filed on
behalf of each of the undersigned without the necessity of filing additional
joint filing agreements. The undersigned acknowledge that each shall be
responsible for the timely filing of such amendments, and for the completeness
and accuracy of the information concerning him or it contained herein and
therein, but shall not be responsible for the completeness and accuracy of the
information concerning the others, except to the extent that he or it knows or
has reason to believe that such information is inaccurate

Dated: January 30, 2017

HUDSON BAY CAPITAL MANAGEMENT, L.P.

By: /s/ Sander Gerber
Name:	Sander Gerber
Title: Authorized Signatory



/s/ Sander Gerber
SANDER GERBER