As of September 12, 2026, the three largest insider holders of ALMU are Mark N. Tompkins (TenPercentOwner, 2.72Mn shares), Mark N. Tompkins (TenPercentOwner, 2.72Mn shares), Mark N. Tompkins (Other, 1.79Mn shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Mark N. Tompkins | Other | 4,506,321 | 0 | 4,506,321 | 72.9% | 05 Feb, 2026 |
| 2 | Jonathan Klamkin | Chief Executive Officer | 2,403 | 1,326,995 | 1,329,398 | 21.5% | 05 Aug, 2026 |
| 3 | Steven Denbaars | Director | 345,209 | 0 | 345,209 | 5.6% | 28 Aug, 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 |
|---|---|---|---|---|---|---|---|---|
| 26 Aug, 2026 | Steven Denbaars | Director | Disposed S | 12,500 | $13.84 | $173.04K | 357,709 | Direct |
| 26 Aug, 2026 | Steven Denbaars | Director | Disposed S | 12,500 | $13.84 | $173.04K | 357,709 | Direct |
| 27 Aug, 2026 | Steven Denbaars | Director | Disposed S | 12,500 | $13.82 | $172.70K | 345,209 | Direct |
| 27 Aug, 2026 | Steven Denbaars | Director | Disposed S | 12,500 | $13.82 | $172.70K | 345,209 | Direct |
| 03 Aug, 2026 | Jonathan Klamkin | Chief Executive Officer | Disposed G | 20,000 | $0.00 | $0 | 1,326,995 | Indirect |
| 03 Aug, 2026 | Jonathan Klamkin | Chief Executive Officer | Acquired G | 20,000 | $0.00 | $0 | 22,403 | Direct |
| 03 Aug, 2026 | Jonathan Klamkin | Chief Executive Officer | Disposed S | 4,190 | $16.29 | $68.26K | 18,213 | Direct |
| 03 Aug, 2026 | Jonathan Klamkin | Chief Executive Officer | Disposed S | 15,810 | $16.85 | $266.38K | 2,403 | Direct |
| 01 Jul, 2026 | Jonathan Klamkin | Chief Executive Officer | Disposed G | 20,000 | $0.00 | $0 | 1,346,995 | Indirect |
| 01 Jul, 2026 | Jonathan Klamkin | Chief Executive Officer | Acquired G | 20,000 | $0.00 | $0 | 22,403 | Direct |
| 01 Jul, 2026 | Jonathan Klamkin | Chief Executive Officer | Disposed S | 19,900 | $21.08 | $419.51K | 2,503 | Direct |
| 01 Jul, 2026 | Jonathan Klamkin | Chief Executive Officer | Disposed S | 100 | $21.56 | $2.16K | 2,403 | Direct |
| 01 Jun, 2026 | Jonathan Klamkin | Chief Executive Officer | Disposed G | 20,000 | $0.00 | $0 | 1,366,995 | Indirect |
| 01 Jun, 2026 | Jonathan Klamkin | Chief Executive Officer | Acquired G | 20,000 | $0.00 | $0 | 22,403 | Direct |
| 01 Jun, 2026 | Jonathan Klamkin | Chief Executive Officer | Disposed S | 900 | $22.19 | $19.97K | 21,503 | Direct |
| 01 Jun, 2026 | Jonathan Klamkin | Chief Executive Officer | Disposed S | 1,400 | $23.32 | $32.65K | 20,103 | Direct |
| 01 Jun, 2026 | Jonathan Klamkin | Chief Executive Officer | Disposed S | 7,900 | $24.39 | $192.64K | 12,203 | Direct |
| 01 Jun, 2026 | Jonathan Klamkin | Chief Executive Officer | Disposed S | 1,600 | $25.12 | $40.19K | 10,603 | Direct |
| 01 Jun, 2026 | Jonathan Klamkin | Chief Executive Officer | Disposed S | 8,200 | $26.25 | $215.21K | 2,403 | Direct |
| 19 May, 2026 | Steven Denbaars | Director | Disposed S | 7,415 | $19.56 | $145.03K | 387,794 | Direct |