Carbios Shares Plunge 27% in Week as China Delay and Leadership Change Rattle Confidence

Carbios shares drop 7.25% to €6.01, down 27% in seven days. New CEO Benoît Grenot inherits oversold stock, delayed Chinese plant, and €5M capital increase pushed to 2026.

Carbios is facing a brutal reality check. The French cleantech company’s stock tumbled 7.25% on Friday to close at €6.01, capping a seven-day rout of 27.24% that has stripped nearly half the group’s market value since January. Year-to-date losses now stand at 48.23%, with the shares hovering just 4.52% above their 52-week trough of €5.75 — a low touched only days ago.

The sell-off coincides with Benoît Grenot taking the chief executive reins on June 1, succeeding Vincent Kamel, who stepped down at the end of May to retire. Far from a honeymoon period, Grenot inherits a stock trading 33.99% below its 200-day moving average of €9.11 and a Relative Strength Index of 29.4, signaling deeply oversold conditions. The market is not giving him the benefit of the doubt.

At the heart of investor anxiety is a double whammy. Carbios’s flagship Chinese project with partner Wankai has been pushed back: the plant, designed to enzymatically recycle 50,000 tonnes of plastic annually, is now slated to start in the first half of 2028. That delay also affects a planned €5 million capital increase from Wankai, which has been rescheduled to the end of 2026. The Chinese venture was supposed to deliver early industrial revenues; instead, those cash flows have been pushed out by at least two years.

The company’s domestic anchor — the Longlaville facility — offers little near-term solace. Carbios reaffirmed in March that it will fund the plant through project financing, targeting production in the first half of 2028. A key milestone is the completion of financing components by the third quarter of 2026. Until that box is ticked, the enzymatic PET recycling venture remains a promise rather than a production line.

Financial runway, at least, is not an immediate concern. Carbios ended 2025 with €59 million in cash across its subsidiaries, enough to cover operating expenses for more than twelve months. The group expects a cash burn of around €20 million in 2026 excluding Longlaville, and it trimmed operating losses by €7 million last year. But with annualised volatility above 58% and a stock that has lost more than a fifth of its value in the past 30 days alone, the market is demanding more than cost control.

Grenot must now demonstrate that the new timelines are credible and that licensing deals — in Europe, North America and South America — are building tangible momentum. The next formal test comes at the annual general meeting in Paris on June 18, followed by half-year results on September 24. Until then, every slip in project financing or partnership execution risks another test of the €5.75 floor.