X0306 4 2017-12-11 0 0001592058 Party City Holdco Inc. PRTY 0001034196 ADVENT INTERNATIONAL CORP/MA 800 BOYLSTON STREET BOSTON MA 02199 0 0 1 0 0001430919 ADVENT INTERNATIONAL GPE VI LP ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET BOSTON MA 02199 0 0 1 0 0001430920 ADVENT INTERNATIONAL GPE VI-A LP ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET BOSTON MA 02199 0 0 1 0 0001430926 ADVENT INTERNATIONAL GPE VI-B LP ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON BOSTON MA 02119 0 0 1 0 0001430925 ADVENT INTERNATIONAL GPE VI-C LP ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET BOSTON MA 02199 0 0 1 0 0001430923 ADVENT INTERNATIONAL GPE VI-D LP ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET BOSTON MA 02199 0 0 1 0 0001430921 ADVENT INTERNATIONAL GPE VI-E LP ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET BOSTON MA 02199 0 0 1 0 0001430922 ADVENT INTERNATIONAL GPE VI-F LP ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET BOSTON MA 02199 0 0 1 0 0001432552 ADVENT INTERNATIONAL GPE VI-G LP ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET BOSTON MA 02199 0 0 1 0 Common Stock 2017-12-11 4 S 0 2558306 12.67 D 19841694 I See Notes The shares of common stock of the Issuer were sold in connection with a block trade of the common stock of the Issuer pursuant to the prospectus supplement, dated December 7, 2017, and accompanying registration statement on Form S-3, dated September 30, 2016. Advent-Party City Acquisition LP ("APCA") directly owns 19,841,694 shares of common stock of the Issuer. The Advent Funds (as defined below) directly own all of the partnership interests in APCA. APCA, together with Advent International Corporation ("AIC"), Advent International LLC ("AILLC"), GPE VI GP Limited Partnership ("GPE VI"), GPE VI GP (Delaware) Limited Partnership ("GPE VI D") and the Advent Funds, are referred to herein as the "Reporting Persons". The shares directly owned by APCA may be deemed beneficially owned by the other Reporting Persons; however, each Reporting Person disclaims beneficial ownership of these securities except to the extent of its respective pecuniary interest therein, if any, and the inclusion of these shares in their report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or any other purpose. AIC is the manager of AILLC, which is the general partner of each of GPE VI, GPE VI D, Advent Partners GPE VI 2008 Limited Partnership ("GPE 2008), Advent Partners GPE VI 2009 Limited Partnership ("GPE 2009"), Advent Partners GPE VI 2010 Limited Partnership ("GPE 2010"), Advent Partners GPE VI-A Limited Partnership ("GPE A"), and Advent Partners GPE VI-A 2010 Limited Partnership ("GPE A 2010", together with GPE 2008, GPE 2009, GPE 2010 and GPE A, collectively, the "Advent Partner Entities"). GPE VI D is the general partner of the following entities: Advent International GPE VI-C Limited Partnership, Advent International GPE VI-D Limited Partnership and GPE VI-E Limited Partnership (collectively, the "GPE VI D Funds"). GPE VI is the general partner of the following entities: Advent International GPE VI-G Limited Partnership, Advent International GPE VI Limited Partnership, Advent International GPE VI-A Limited Partnership, Advent Internal GPE VI-B Limited Partnership, and Advent International GPE VI-F Limited Partnership (collectively, the "GPE VI Funds" and together with the GPE VI D Funds and the Advent Partner Entities, collectively the "Advent Funds"). This Form 4 is the first of two Forms 4 being filed relating to the same event. The 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. Each Form 4 will be filed by Designated Filer Advent International Corporation. /s/ Richard Terranova, Attorney-in-Fact 2017-12-13 /s/ Richard Terranova, Attorney-in-Fact 2017-12-13 /s/ Richard Terranova, Attorney-in-Fact 2017-12-13 /s/ Richard Terranova, Attorney-in-Fact 2017-12-13 /s/ Richard Terranova, Attorney-in-Fact 2017-12-13 /s/ Richard Terranova, Attorney-in-Fact 2017-12-13 /s/ Richard Terranova, Attorney-in-Fact 2017-12-13 /s/ Richard Terranova, Attorney-in-Fact 2017-12-13 /s/ Richard Terranova, Attorney-in-Fact 2017-12-13