GKN Garden Grove Gets a Clean Bill of Health, but Can Melrose Sustain a $500-Plus Share Price on Promises Alone?

Shares of Melrose Industries surged as much as 8.7% to £502.32 on August 25 after the company announced that criminal charges against its GKN Aerospace facility in Garden Grove, California, have been dropped and that full manufacturing is targeted for September 28, 2026. The rally snaps a five-session slide that had dragged the stock from £493.30 to £470.30, but investors now face a harder question: how much of the recovery is already priced in? GKN Garden Grove Clears Its Biggest Legal Hurdle, but Is the Real Cost of the Chemical Crisis Still Ahead?

Shares of Melrose Industries jumped 8.7% to £502.32 on August 25 after its subsidiary GKN Aerospace said the Orange County District Attorney dropped its criminal investigation into a May chemical leak at the Garden Grove, California plant — and that full manufacturing will resume by September 28. The rally snaps a five-session slide but leaves investors weighing whether a cleared legal cloud justifies paying up for a stock still carrying tens of millions in cleanup costs.

• The Chemical Leak Forced 40,000 People From Their Homes — and the Criminal Case Was a Cloud Over the Whole Company. On May 21, a storage tank containing roughly 7,000 gallons of methyl methacrylate — a flammable chemical used in plastics — overheated and began venting at GKN's Garden Grove factory.

By the next day, roughly 40,000 Orange County residents were under mandatory evacuation.

DA Todd Spitzer's office had ordered preservation of maintenance logs, telemetry records, and internal communications. With that criminal probe now closed, the most severe legal outcome — potential criminal liability that could have threatened GKN's operating license — is off the table.

• The Plant Makes Parts Nobody Else Easily Can, and Every Day Offline Hurts. The Garden Grove facility supplies windshields and cabin windows for Boeing, Airbus A350, and Lockheed Martin's F-35.

It employed at least 540 people, and an expansion to double F-35 canopy production capacity was scheduled for completion by January 2027. A September 28 restart — over four months of disruption — means this expansion timeline is almost certainly pushed out, compressing the window to capture growing defence demand.

• The Financial Damage Is Real but Manageable — If Nothing Else Goes Wrong. Melrose reported first-half adjusted pretax profit of £282 million, up 18% year-on-year, but the incident already shaved £16 million off revenue and £9 million off operating profit.

The company guided for an additional £25–30 million in second-half costs.

It also paused its £175 million share buyback programme. Against full-year revenue guidance of £3.75–3.95 billion and targeted operating profit of £700–750 million , the hit is roughly 3–5% of earnings — noticeable, not fatal.

• Civil Lawsuits and a $100 Million Claims Programme Still Loom. The dropped criminal charges do not resolve a class-action suit or the up-to-$100 million community claims programme. A DiCello Levitt class action remains active in Orange County Superior Court , and a prior 2025 settlement involving air quality violations shows regulators already had this facility on their radar. The final civil bill could easily eclipse the operational costs disclosed so far — a risk today's buyers are choosing to look past.