Koppers Holdings Inc. – Underwriting Agreements Watch

from SCHEDULE 13D 1 page Transactions in the Shares During the Past Sixty Days Shares of Common Stock Purchased/(Sold) Price Per Share($) Date of Purchase/Sale Simcoe Partners, L.P. 14,094 43.0468 05/11/2026 53,057 43.1932 05/12/2026 51,739 42.6869 05/13/2026 67,451 43.1963 05/14/2026 24,807 40.8226 05/15/2026 40,107 41.2995 05/18/2026 55,255 39.0508 05/19/2026 Simcoe Select, L.P. 18,747 43.1932 05/12/2026 18,282 42.6869 05/13/2026 23,833 43.1963 05/14/2026 8,765 40.8226 05/15/2026 14,173 41.2995 05/18/2026 3,045 39.0508 05/19/2026 Sdr Partners, LLC 906 43.0468 05/11/2026 1,985 43.1932 05/12/2026 1,936 42.6869 05/13/2026 2,524 43.1963 05/14/2026 928 40.8226 05/15/2026 1,501 41.2995 05/18/2026 1,440 39.0508 05/19/2026

from 8-K 42 pages Koppers Holdings Inc. Common Stock (Par Value $0.01 Per Share) at Market Issuance Sales Agreement

from 8-K 31 pages Koppers Inc. $500,000,000 6.00% Senior Notes Due 2025 Purchase Agreement

from S-1/A 33 pages Koppers Holdings Inc. Common Stock Form of Underwriting Agreement