1 unchanged sentence
Trading Arrangements
−Removed: During the three months ended September 30, 2025, none of the Company’s directors or executive officers adopted , modified or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” each as defined in Item 408(a) of Regulation S-K.
−Removed: Share Repurchase Program Modification
−Removed: On October 30, 2025, our Board amended our Stock Repurchase Program to remove the limitation that all repurchases must be made within the four-year period from the date of original approval on April 27, 2022.
+Added: During the three months ended March 31, 2026, none of the Company’s directors or executive officers adopted , modified or terminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” each as defined in Item 408(a) of Regulation S-K.
The following exhibits are being filed or furnished as part of this Quarterly Report on Form 10-Q:
−Removed: 2.1 Stock Purchase Agreement, dated as of September 10, 2025, by and between Ecovyst Inc.
−Removed: and Technip Energies N.V.
−Removed: (incorporated by reference to Exhibit 2.1 to the Company’s Form 8-K, filed September 11, 2025)
−Removed: 10.1* Transition Agreement and General Release, effective as of August 11, 2025, between Ecovyst Inc.
−Removed: and George L.
31.1 Certification of Chief Executive Officer of Ecovyst Inc.
9 unchanged sentences
101 The following materials from the Quarterly Report on Form 10-Q of Ecovyst Inc.
−Removed: for the quarter ended September 30, 2025, formatted in Inline XBRL:
−Removed: (i) Condensed Consolidated Statements of (Loss) Income, (ii) Condensed Consolidated Statements of Comprehensive (Loss) Income, (iii) Condensed Consolidated Balance Sheets, (iv) Condensed Consolidated Statements of Stockholders’ Equity, (v) Condensed Consolidated Statements of Cash Flows, (vi) Notes to Condensed Consolidated Financial Statements and (vii) document and entity information, tagged as blocks of text and including detailed tags
+Added: for the quarter ended March 31, 2026, formatted in Inline XBRL:
+Added: (i) Condensed Consolidated Statements of Income (Loss), (ii) Condensed Consolidated Statements of Comprehensive Income (Loss), (iii) Condensed Consolidated Balance Sheets, (iv) Condensed Consolidated Statements of Stockholders’ Equity, (v) Condensed Consolidated Statements of Cash Flows, (vi) Notes to Condensed Consolidated Financial Statements and (vii) document and entity information, tagged as blocks of text and including detailed tags
104 The cover page from the Quarterly Report on Form 10-Q of Ecovyst Inc.
−Removed: for the quarter ended September 30, 2025, formatted in Inline XBRL and included as Exhibit 101
−Removed: * Management contract or compensatory plan
+Added: for the quarter ended March 31, 2026, formatted in Inline XBRL and included as Exhibit 101
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.
−Removed: November 5, 2025 By:
+Added: May 5, 2026 By:
/s/ MICHAEL FEEHAN
3 unchanged sentences
Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.