Koppers Holdings Inc. shares fell after the Company reported third-quarter adjusted earnings per share of $0.77 compared to Street expectations of roughly $1.32 to $1.37, and revenue of $499.1 million compared to estimates of approximately $514.6 million to $519.7 million. During the period, net income fell approximately 38% and adjusted EBITDA declined 18% to $58 million. In addition, the Company reduced its full-year 2026 financial guidance, cutting adjusted EBITDA to approximately $220 million to $225 million and adjusted EPS to $3.10 to $3.25. Management attributed the results and revised outlook to raw-material, logistics, and SG&A cost pressures, alongside demand weakness. Chief Executive Officer Leroy Ball previously stated during a first-quarter 2026 call that "we have more working against us than for us right now" and that "the market continues to be in turmoil." Additionally, during the fourth-quarter 2025 earnings call, CEO Leroy Ball stated that "The Catalyst benefits for Performance Chemicals targeted in 2026 are mostly commercially driven and are already secured-" despite persistent operational and cost headwinds. Company filings further disclosed adverse developments including pre-tax charges of $227 million to $262 million and a $3.8 million Portland Harbor environmental accrual. The investigation concerns whether Koppers Holdings Inc. adequately disclosed raw-material, logistics, and SG&A cost pressures ahead of its third-quarter financial results and full-year 2026 guidance cut.