PC CONNECTION INC 10-Q

Item 5. Other Information ​ Director and Officer Trading Arrangements ​ On March 9, 2026 , Patricia Gallup , the Chief Administrative Officer of the Company and the Chair of the Board of Directors , adopted a Rule 10b5-1 trading agreement for the sale of securities of the Company’s common stock that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). Ms. Gallup’s Rule 10b5-1 trading agreement, which has a term until December 17, 2026 , provides for the sale of up to 200,000 shares of common stock pursuant to the terms of the plan. 26 Table of Contents None of our other directors or officers (as defined in Exchange Act Rule 16a-1(f)) adopted or terminated a Rule 10b5-1 trading agreement or a non-Rule 10b5-1 trading agreement (as each term is defined in Item 408(c) of Regulation S-K) during the first quarter of 2026. ​ 27 Table of Contents Item 6. Exhibits ​ ​ ​ ​ ​ Exhibit Number ​ Description ​ ​ ​ ​ 3.1 ​ ​ Amended and Restated Certificate of Incorporation of PC Connection, Inc., as amended (incorporated by reference to Exhibit 3.1 to the Company’s registration statement on Form S-4 (333-63272) filed on June 19, 2001) . ​ ​ ​ ​ 3.2 ​ ​ Amended and Restated Bylaws of PC Connection, Inc. (incorporated by reference to Exhibit 3.1 to the Company’s current report on Form 8-K, filed on January 9, 2008). ​ ​ ​ ​ 10.1 * ​ Director Compensation and Executive Bonus Plan, as amended. ​ ​ ​ ​ 10.2 * ​ Amendment No. 3, dated January 22, 2026, to Lease Agreement between the Registrant and Wilmington Investors, LLC, dated August 27, 2014, for property located at 3336 Progress Way, Building 11, Wilmington, OH. ​ ​ ​ ​ 10.3 * ​ Amendment No. 4, dated January 26, 2026, to Lease Agreement between the Registrant and Wilmington Investors, LLC, dated August 27, 2014, for property located at 3336 Progress Way, Building 11, Wilmington, OH. ​ ​ ​ ​ 31.1 * ​ Certification of the Company’s President and Chief Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. ​ ​ ​ ​ 31.2 * ​ Certification of the Company’s Senior Vice President and Chief Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002. ​ ​ ​ ​ 32.1 * ​ Certification of the Company’s President and Chief Executive Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. ​ ​ ​ ​ 32.2 * ​ Certification of the Company’s Senior Vice President and Chief Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002. ​ ​ ​ ​ 101.INS * ​ Inline XBRL Instance Document* - The Instance document does not appear in the interactive data file because its XBRL tags are embedded within the inline XBRL document. ​ ​ ​ ​ 101.SCH * ​ Inline XBRL Taxonomy Extension Schema Document. ​ ​ ​ ​ 101.CAL * ​ Inline XBRL Taxonomy Calculation Linkbase Document. ​ ​ ​ ​ 101.DEF * ​ Inline XBRL Taxonomy Extension Definition Linkbase Document ​ ​ ​ ​ 101.LAB * ​ Inline XBRL Taxonomy Label Linkbase Document. ​ ​ ​ ​ 101.PRE * ​ Inline XBRL Taxonomy Presentation Linkbase Document. ​ ​ ​ ​ 104 * ​ Cover Page Interactive Data File (formatted as Inline XBRL with applicable taxonomy extension information contained in Exhibits 101). * Submitted electronically herewith. ​ Attached as Exhibit 101 to this report are the following formatted in XBRL (Extensible Business Reporting Language): (i) Condensed Consolidated Balance Sheets at March 31, 2026 and December 31, 2025, (ii) Condensed Consolidated Statements of Income for the three months ended March 31, 2026 and 2025, (iii) Condensed Consolidated Statements of Other Comprehensive Income for the three months ended March 31, 2026 and 2025, (iv) Condensed Consolidated Statements of Stockholders’ Equity for the three months ended March 31, 2026 and 2025, (v) Condensed Consolidated Statements of Cash Flows for the three months ended March 31, 2026 and 2025, and (vi) Notes to Unaudited Condensed Consolidated Financial Statements. 28 Table of Contents SIGNATURE S Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized. PC CONNECTION, INC. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Date: April 29, 2026 ​ By: /s/ TIMOTHY J. MCGRATH ​ ​ ​ ​ Timothy J. McGrath ​ ​ ​ ​ President and Chief Executive Officer (Duly Authorized Officer) ​ ​ ​ ​ ​ Date: April 29, 2026 ​ By: /s/ THOMAS C. BAKER ​ ​ ​ ​ Thomas C. Baker ​ ​ ​ ​ Senior Vice President, Chief Financial Officer and Treasurer (Principal Financial and Accounting Officer) ​ ​ ​ ​ 29