Mesa Laboratories, Inc.
A maker of quality-control tools for hospitals, labs, and pharmaceutical companies, Mesa Laboratories builds biological indicators—like its EZTest and Smart-Read lines—that verify sterilization equipment actually kills germs. Founded in Lakewood, Colorado in 1982, it grew from a small instrumentation and calibration shop into a global player through steady acquisitions, including Agena Bioscience and GKE. The name nods to the flat-topped hills common across its home state, a fitting touch for a company rooted in the American West.
Granted 41.2K · Sold 18.1K
Granted 87.9K · Sold 31.8K
Granted 2.2K · Sold 12.1K
Granted 30
Granted 5.5K · Sold 6.0K
Granted 40.3K · Sold 24.4K
Granted 5.0K · Bought 3.5K
Granted 18.8K · Sold 9.2K
Granted 3.6K · Bought 1.8K
Granted 3.7K
Granted 1.7K · Sold 835
Granted 3.7K · Sold 230
Granted 2.1K · Bought 1.3K
Granted 18 · Sold 621
Granted 989 · Sold 560
| Insider | Stake change | Holds now | Granted / vested | Bought | Sold |
|---|---|---|---|---|---|
| Sullivan John JamesDirector · 33 transactions | +28.9% | 70.1K | 41.2K | — | 18.1K |
| Owens Gary MPresident and CEO · 29 transactions | +248.6% | 64.1K | 87.9K | — | 31.8K |
| Schmieder John BradleyDirector · 12 transactions | -11.6% | 62.8Kas of Sep 2023 | 2.2K | — | 12.1K |
| Mesa Laboratories Inc /Co/Director · 1 transaction | — | 29.8Kas of Jun 2022 | 30 | — | — |
| Guillemin EvanDirector · 10 transactions | -1.9% | 29.2Kas of Sep 2022 | 5.5K | — | 6.0K |
| Sakys JohnCFO · 59 transactions | — | 19.8K | 40.3K | — | 24.4K |
| Ladiwala Shiraz ShabanaliDirector · 6 transactions | — | 8.5K | 5.0K | 3.5K | — |
| Archbold Brian DavidSVP Operations · 34 transactions | +4040.9% | 6.4K | 18.8K | — | 9.2K |
| Tripeny R TonyDirector · 5 transactions | — | 5.4K | 3.6K | 1.8K | — |
| Alltoft Jennifer SadieDirector · 4 transactions | +301.5% | 4.9Kas of Aug 2025 | 3.7K | — | — |
| Dinoia GregorySVP Commercial · 5 transactions | +40.9% | 4.2Kas of Jun 2022 | 1.7K | — | 835 |
| Hall ShannonDirector · 5 transactions | +454.1% | 4.2Kas of Aug 2025 | 3.7K | — | 230 |
| Capone Mark ChristopherDirector · 3 transactions | — | 3.4K | 2.1K | 1.3K | — |
| Kelly David MDirector · 3 transactions | -18.8% | 2.6Kas of Nov 2021 | 18 | — | 621 |
| Crennen Lyndsey ElizabethCAO · 6 transactions | — | 2.0K | 989 | — | 560 |
Select a row to see that insider’s individual transactions. Sum of the holdings confirmed in the 12 months before this insider's last filing. A Form 4 reports a holding per line — held directly, or through a named trust, partnership or foundation, and in each share class separately — never a person’s total. Lines not restated in that time are left out and shown apart: an active filer restates what they still hold, so a line they did not restate is more often an entity since renamed, whose shares a successor line reports too. An amber marker means some were left out.
Net open-market activity over the last 5 years: -97.1K shares. Grants, option exercises and tax withholding are excluded — they are compensation mechanics, not decisions to buy or sell.