CSTE's three largest insider shareholders as of September 29, 2026 are Ron Mosberg (Gen. Counsel Corp. Sec., 4.62K shares), David Vincent Cullen (Managing Director, Apac, 675 shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Ron Mosberg | Gen. Counsel Corp. Sec. | 0 | 4,625 | 4,625 | 87.3% | 24 Sep, 2026 |
| 2 | David Vincent Cullen | Managing Director, Apac | 675 | 0 | 675 | 12.7% | 20 May, 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 |
|---|---|---|---|---|---|---|---|---|
| 24 Sep, 2026 | Ron Mosberg | Gen. Counsel Corp. Sec. | Disposed S | 64 | $2.82 | $180 | 4,625 | Indirect |
| 19 May, 2026 | David Vincent Cullen | Managing Director, Apac | Disposed S | 7,025 | $1.57 | $11.03K | 675 | Direct |