The Zacks Pollution Control industry (Rank #45) benefits from strong demand for air pollution control products driven by rising greenhouse gas emissions and strict global regulations. However, the industry faces headwinds from the growing adoption of renewable energy sources and electric vehicles. Four key stocks are highlighted: CECO Environmental (Rank #1), LiqTech (Rank #2), Donaldson (Rank #3), and Fuel Tech (Rank #3). The industry has underperformed the S&P 500 over the past year, declining 2.4% versus the index's 16.8% gain.

Parker-Hannifin reported strong momentum in its Aerospace Systems segment with 13.3% organic sales growth and 18% order increases in fiscal Q4 2026. The company completed the acquisition of Filtration Group and has a pending deal for CIRCOR's aerospace business. However, rising operating expenses, $6.77 billion in long-term debt, and $401 million in annual interest expenses pose challenges to profitability.

CECO Environmental Corp. reported a 73% year-over-year increase in adjusted EBITDA to $40.2 million in Q2 2026, with margins expanding 154 basis points to 14.1%. The company raised its 2026 adjusted EBITDA guidance to $200-$225 million and expects mid-teens margins, supported by a $1.8 billion backlog and the Thermon acquisition.

CECO Environmental Corp. is experiencing strong momentum in its Industrial Process Solutions segment with Q2 2026 revenues up 8.4% YoY to $61.7M and orders surging 81% YoY to $90.3M. The company raised its 2026 revenue guidance to $1.300-$1.375B and reported a $1.82B backlog (up 129.4% from year-end 2025), providing strong visibility for future quarters. However, CECO trades at a premium valuation of 23.84X forward P/E versus the industry average of 19.80X.

The global HVAC filters market is projected to grow from USD 4.66 billion in 2026 to USD 6.21 billion by 2031, driven by increased demand for high-efficiency air filtration, stringent air quality regulations, and indoor air quality awareness. Synthetic polymer filters hold significant market share, while electrostatic precipitators and pharmaceutical applications represent fastest-growing segments. Europe emerges as the second-fastest-growing regional market.

Donaldson Company reported strong third-quarter fiscal 2026 results with record sales of $995.1 million, exceeding analyst expectations. The company raised its full-year earnings and revenue guidance, driven by strength in Mobile Solutions and Life Sciences segments. Shares gained 2.32% on the news.

The midstream oil & gas filtration market is projected to grow from USD 2.80 billion in 2025 to USD 3.73 billion by 2030, at a CAGR of 5.9%. Coalescer filters and fiberglass media are the fastest-growing segments, while pipeline transportation and Asia Pacific represent major market opportunities. Key drivers include LNG capacity buildout, aging infrastructure, and stricter emissions regulations.

Ten large-cap stocks experienced significant declines during the week of February 23-27, 2026. Notable losers include First Solar (down 18.59% due to worse-than-expected Q4 results and below-estimate FY26 guidance), Zoom Communications (down 17.38% following mixed Q4 results and weak forward guidance), and Novo Nordisk (down 6.59% after announcing Chinese trial results and potential price cuts for Ozempic and Wegovy). Other major decliners include Donaldson, TopBuild, Corebridge Financial, Nu Holdings, KKR, Korea Electric Power, and Pure Storage.

Donaldson Company's stock dropped 18.2% after missing earnings estimates despite posting record Q2 results. The company trimmed its fiscal 2026 EPS guidance due to weakness in trucking and aerospace/defense sectors. However, the planned $820 million acquisition of Facet, a filtration solutions company serving aerospace, defense, and power generation, positions the company for significant growth in 2026, making the current dip potentially a buying opportunity.

Donaldson Company reported Q1 fiscal 2026 results with sales rising 3.9% to $935.4 million, beating consensus estimates. The company raised its annual guidance and saw growth across multiple business segments, particularly in Mobile Solutions and Life Sciences.

Donaldson reported strong Q4 and fiscal 2025 results with record revenue of $3.7 billion, 16.4% operating margin, and plans for continued growth in fiscal 2026 through operational efficiency and aftermarket expansion.

Donaldson Company reported record sales of $981 million in Q4 fiscal 2025, with a 4.8% revenue increase and 9.6% adjusted EPS growth. The company projects continued growth in fiscal 2026, targeting $3.8 billion in sales and an EPS around $4.00.