As of September 29, 2026, Mesa Laboratories's top three insider holders are Gary M Owens (President And Ceo, 64.14K shares), John Bradley Schmieder (Director, 62.76K shares), John James Sullivan (Director, 44.78K shares).
| # | Insider | Position | Direct | Indirect | Total | Share of Insiders | Last Filed |
|---|---|---|---|---|---|---|---|
| 1 | Gary M Owens | President And Ceo | 64,135 | 0 | 64,135 | 22.1% | 28 Oct, 2025 |
| 2 | John Bradley Schmieder | Director | 62,760 | 0 | 62,760 | 21.6% | 19 Sep, 2023 |
| 3 | Laboratories Inc /Co/ Mesa | Director | 29,788 | 0 | 29,788 | 10.3% | 16 Jun, 2022 |
| 4 | Evan Guillemin | Director | 29,207 | 0 | 29,207 | 10.1% | 02 Sep, 2022 |
| 5 | John James Sullivan | President And Ceo | 20,618 | 0 | 20,618 | 7.1% | 17 Aug, 2026 |
| 6 | John Sakys | Cfo | 19,785 | 0 | 19,785 | 6.8% | 23 Jun, 2026 |
| 7 | Shiraz Shabanali Ladiwala | Director | 12,333 | 0 | 12,333 | 4.2% | 17 Aug, 2026 |
| 8 | R Tony Tripeny | Director | 9,082 | 0 | 9,082 | 3.1% | 17 Aug, 2026 |
| 9 | Jennifer Sadie Alltoft | Director | 7,662 | 0 | 7,662 | 2.6% | 17 Aug, 2026 |
| 10 | Siddhartha Kadia | President And Ceo | 0 | 7,093 | 7,093 | 2.4% | 17 Aug, 2026 |
| 11 | Shannon Hall | Director | 6,973 | 0 | 6,973 | 2.4% | 17 Aug, 2026 |
| 12 | Brian David Archbold | Svp Operations | 6,377 | 0 | 6,377 | 2.2% | 23 Jun, 2026 |
| 13 | Mark Christopher Capone | Director | 6,213 | 0 | 6,213 | 2.1% | 17 Aug, 2026 |
| 14 | Gregory Dinoia | Svp Commercial | 3,634 | 0 | 3,634 | 1.3% | 22 Jun, 2022 |
| 15 | David M Kelly | Director | 2,600 | 0 | 2,600 | 0.9% | 09 Nov, 2021 |
| 16 | Lyndsey Elizabeth Crennen | Cao | 2,020 | 0 | 2,020 | 0.7% | 23 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 |
|---|---|---|---|---|---|---|---|---|
| 09 Sep, 2009 | Jennifer Sadie Alltoft | Director | Acquired A | 1,774 | $0.00 | $0 | 1,774 | Direct |
| 09 Sep, 2026 | Shiraz Shabanali Ladiwala | Director | Acquired A | 2,510 | $0.00 | $0 | 2,510 | Direct |
| 09 Sep, 2026 | John James Sullivan | Director | Acquired A | 1,774 | $0.00 | $0 | 1,774 | Direct |
| 09 Sep, 2026 | Shannon Hall | Director | Acquired A | 1,774 | $0.00 | $0 | 1,774 | Direct |
| 09 Sep, 2026 | R Tony Tripeny | Director | Acquired A | 1,774 | $0.00 | $0 | 1,774 | Direct |
| 09 Sep, 2026 | Mark Christopher Capone | Director | Acquired A | 2,423 | $0.00 | $0 | 2,423 | Direct |
| 15 Aug, 2026 | John James Sullivan | Director | Acquired M | 2,784 | $0.00 | $0 | 20,618 | Direct |
| 15 Aug, 2026 | Mark Christopher Capone | Director | Acquired M | 2,784 | $0.00 | $0 | 6,213 | Direct |
| 15 Aug, 2026 | R Tony Tripeny | Director | Acquired M | 2,784 | $0.00 | $0 | 9,082 | Direct |
| 15 Aug, 2026 | Jennifer Sadie Alltoft | Director | Acquired M | 2,784 | $0.00 | $0 | 7,662 | Direct |
| 13 Aug, 2026 | Siddhartha Kadia | President And Ceo | Acquired P | 7,093 | $112.80 | $800.09K | 7,093 | Indirect |
| 13 Aug, 2026 | John James Sullivan | Director | Disposed S | 7,093 | $112.80 | $800.09K | 17,834 | Direct |
| 15 Aug, 2026 | Shiraz Shabanali Ladiwala | Director | Acquired M | 3,810 | $0.00 | $0 | 12,333 | Direct |
| 15 Aug, 2026 | Shannon Hall | Director | Acquired M | 2,784 | $0.00 | $0 | 6,973 | Direct |
| 15 Aug, 2026 | R Tony Tripeny | Director | Disposed M | 2,784 | $0.00 | $0 | 0 | Direct |
| 15 Aug, 2026 | Mark Christopher Capone | Director | Disposed M | 2,784 | $0.00 | $0 | 0 | Direct |
| 15 Aug, 2026 | Jennifer Sadie Alltoft | Director | Disposed M | 2,784 | $0.00 | $0 | 0 | Direct |
| 15 Aug, 2026 | Shiraz Shabanali Ladiwala | Director | Disposed M | 3,810 | $0.00 | $0 | 0 | Direct |
| 15 Aug, 2026 | Shannon Hall | Director | Disposed M | 2,784 | $0.00 | $0 | 0 | Direct |
| 15 Aug, 2026 | John James Sullivan | Director | Disposed M | 2,784 | $0.00 | $0 | 0 | Direct |