As of August 29, 2026, the three largest insider holders of CELC are Bros. Advisors Lp Baker (Other, 4.37Mn shares), Brian F. Sullivan (Chief Executive Officer, 1.75Mn shares), Brian F. Sullivan (Chief Executive Officer, 1.45Mn shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Bros. Advisors Lp Baker | TenPercentOwner | 0 | 7,211,484 | 7,211,484 | 71.6% | 10 Sep, 2025 |
| 2 | Brian F. Sullivan | Chief Executive Officer | 1,450,199 | 0 | 1,450,199 | 14.4% | 18 Aug, 2026 |
| 3 | Lance G. Laing | Chief Science Officer | 1,271,000 | 0 | 1,271,000 | 12.6% | 18 Aug, 2026 |
| 4 | Richard Nigon | Director | 80,565 | 0 | 80,565 | 0.8% | 09 Jun, 2026 |
| 5 | Vicky Hahne | Chief Financial Officer | 37,808 | 0 | 37,808 | 0.4% | 18 Aug, 2026 |
| 6 | Leo Furcht | Director | 12,530 | 0 | 12,530 | 0.1% | 09 Jun, 2026 |
| 7 | Richard E Buller | Director | 0 | 7,789 | 7,789 | 0.1% | 20 May, 2026 |
| 8 | Charles R Romp | Director | 1,745 | 0 | 1,745 | 0.0% | 09 Jun, 2026 |
| 9 | David Dalvey | Director | 1,530 | 0 | 1,530 | 0.0% | 09 Jun, 2026 |
Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.
| Date | Insider | Position | Transaction | Shares | Price | Value | Shares Held After | Ownership |
|---|---|---|---|---|---|---|---|---|
| 14 Aug, 2026 | Vicky Hahne | Chief Financial Officer | Acquired A | 16,000 | $0.00 | $0 | 37,808 | Direct |
| 14 Aug, 2026 | Brian F. Sullivan | Chief Executive Officer | Acquired A | 80,000 | $0.00 | $0 | 1,450,199 | Direct |
| 14 Aug, 2026 | Lance G. Laing | Chief Science Officer | Acquired A | 20,000 | $0.00 | $0 | 1,271,000 | Direct |
| 14 Aug, 2026 | Vicky Hahne | Chief Financial Officer | Acquired A | 10,000 | $0.00 | $0 | 10,000 | Direct |
| 14 Aug, 2026 | Lance G. Laing | Chief Science Officer | Acquired A | 10,000 | $0.00 | $0 | 10,000 | Direct |
| 14 Aug, 2026 | Brian F. Sullivan | Chief Executive Officer | Acquired A | 120,000 | $0.00 | $0 | 120,000 | Direct |
| 05 Jun, 2026 | Charles R Romp | Director | Acquired A | 1,530 | $0.00 | $0 | 1,745 | Direct |
| 05 Jun, 2026 | David Dalvey | Director | Acquired A | 1,530 | $0.00 | $0 | 1,530 | Direct |
| 05 Jun, 2026 | Leo Furcht | Director | Acquired A | 1,530 | $0.00 | $0 | 12,530 | Direct |
| 05 Jun, 2026 | Richard Nigon | Director | Acquired A | 1,530 | $0.00 | $0 | 80,565 | Direct |
| 02 Jun, 2026 | Lance G. Laing | Chief Science Officer | Acquired M | 1,000 | $9.89 | $9.89K | 1,251,000 | Direct |
| 02 Jun, 2026 | Lance G. Laing | Chief Science Officer | Disposed M | 1,000 | $0.00 | $0 | 20,250 | Direct |
| 19 May, 2026 | Richard E Buller | Director | Disposed G | 1,029 | $0.00 | $0 | 0 | Direct |
| 19 May, 2026 | Richard E Buller | Director | Acquired G | 1,029 | $0.00 | $0 | 7,789 | Indirect |
| 04 May, 2026 | David Dalvey | Director | Disposed S | 25,000 | $140.68 | $3.52Mn | 65,000 | Indirect |
| 09 Apr, 2026 | Richard Nigon | Director | Disposed G | 10,000 | $0.00 | $0 | 79,035 | Direct |
| 31 Mar, 2026 | Richard E Buller | Director | Acquired M | 3,000 | $5.10 | $15.30K | 9,760 | Indirect |
| 31 Mar, 2026 | Richard E Buller | Director | Disposed S | 2,325 | $110.11 | $256.00K | 7,435 | Indirect |
| 31 Mar, 2026 | Richard E Buller | Director | Disposed S | 675 | $110.83 | $74.81K | 6,760 | Indirect |
| 31 Mar, 2026 | Richard E Buller | Director | Disposed M | 3,000 | $0.00 | $0 | 9,654 | Indirect |