Updated Jul 16, 2026 · Last SEC filing 2026-06-17
CENTURY ALUMINUM CO (CENX) has filed 5 SEC Form 4 insider transactions in the last 90 days, with the most recent on 2026-06-17. 2 Form 8-K material event filings were reported by CENX in the last 90 days. 1 Form 144 notices of proposed sale were filed for CENX stock. InsiderAlpha tracks every CENX SEC filing — Form 4, Form 144, and 8-K — in real time, including Rule 10b5-1 plan detection.
| SIC classification | Primary Production of Aluminum (SIC 3334) |
|---|---|
| SEC CIK | 0000949157 |
| Form 4 filings (90d) | 5 |
|---|---|
| Form 8-K filings (90d) | 2 |
| Form 144 notices (90d) | 1 |
| Latest Form 4 filing | 2026-06-17 |
| Date | Insider | Role | Transaction | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|
| Berntzen Jarl | Director | A — Grant or award | 2.2K | $0.00 | — | SEC | |
| Olivier Tamla A | Director | A — Grant or award | 2.2K | $0.00 | — | SEC | |
| Michelmore Andrew G | Director | A — Grant or award | 2.2K | $0.00 | — | SEC | |
| GLASSER ERROL | Director | A — Grant or award | 2.2K | $0.00 | — | SEC | |
| Michelmore Andrew G | Director | F — Tax withholding / forfeiture | 652 | $54.55 | $36K | SEC | |
| Bush Jennifer Mary | Director | A — Grant or award | 2.2K | $0.00 | — | SEC | |
| Trpkovski Peter A | EVP, CFO | S — Open-market sale | 16.7K | $50.51 | $845K | SEC | |
| Gary Jesse E | President and CEO | S — Open-market sale [10b5-1] | 150.0K | $55.47 | $8.32M | SEC | |
| Calloway Kenneth L | SVP, Human Resources | S — Open-market sale | 18.0K | $58.00 | $1.04M | SEC | |
| Hoffman Robert F | SVP, IT and CAO | S — Open-market sale | 10.5K | $56.51 | $595K | SEC | |
| GLENCORE INTERNATIONAL AG | 10% Owner | S — Open-market sale | 6.32M | $51.75 | $326.81M | SEC | |
| Hoffman Robert F | SVP, IT and CAO | S — Open-market sale | 10.0K | $56.33 | $563K | SEC | |
| Aboud Matt | SVP, Strategy & Business Dev't | S — Open-market sale | 3.0K | $52.67 | $156K | SEC | |
| Aboud Matt | SVP, Strategy & Business Dev't | S — Open-market sale | 12.1K | $52.50 | $637K | SEC | |
| Hafberg Agust F | SVP & Chief Commercial Officer | S — Open-market sale | 22.9K | $51.24 | $1.17M | SEC |
All transactions sourced from SEC EDGAR Form 4 filings for CENTURY ALUMINUM CO (CENX). Updated in real time as new filings are submitted to the SEC.
| Insider | Form 4 filings | Total transaction value |
|---|---|---|
| Michelmore Andrew G | 2 | $36K |
| Bush Jennifer Mary | 1 | — |
| GLASSER ERROL | 1 | — |
| Berntzen Jarl | 1 | — |
| Olivier Tamla A | 1 | — |
Form 144 must be filed before insiders sell restricted or control stock above SEC thresholds. A cluster of Form 144 notices often precedes a wave of insider distribution.
SEC Form 4 transactions are reported with a one-letter code indicating the type of transaction. Common codes you'll see in CENX insider filings:
| P | Open-market purchase by the insider |
|---|---|
| S | Open-market sale by the insider |
| A | Grant, award, or other acquisition from the issuer |
| M | Exercise or conversion of derivative security (e.g. options) |
| F | Payment of exercise price or tax liability via share withholding |
| G | Bona-fide gift of securities |
| D | Disposition to the issuer (e.g. share buyback participation) |
| J | Other acquisition or disposition |
| X | Exercise of in-the-money or at-the-money derivative security |
| C | Conversion of derivative security |
| V | Transaction voluntarily reported earlier than required |
Open the live CENX dashboard on InsiderAlpha for real-time alerts, charting, and full historical filing search.