Mesa Laboratories MLAB Insider Ownership

Updated Oct 10, 2026

In the last 12 months, insiders at Mesa Laboratories made open-market purchases of $1.35 million (14.11K shares) and open-market sales of $1.57 million (15.37K shares).

• A count shows 4 insiders buying MLAB stock on the open market over the past 12 months and 4 insiders selling.
• Among Mesa Laboratories' insiders, the largest open-market purchases in the past 12 months were by Siddhartha Kadia (President and CEO), totaling $800,090 (7.09K shares), most recently on August 13, 2026.
• Conversely, John James Sullivan (Director) was MLAB's largest open-market seller in the past 12 months, with $800,090 of sales (7.09K shares); the latest was on August 13, 2026.
• Away from the open market, MLAB insiders received 4.4K shares in stock awards, acquired 31.16K shares through option exercises and conversions and gave away 2K shares as gifts over the last 12 months.
• Business Quant data puts insider holdings in MLAB at 207.4K shares across insiders' latest Form 4 filings, up 9.85% from 188.8K shares at the end of Q2 2026.
• By type of ownership, MLAB insiders hold 74.83% of their shares directly (155.2K shares) and 25.17% indirectly (52.2K shares).
• Holdings in Mesa Laboratories stock are reported by 11 insiders, the officers, directors and 10% owners who have filed a Form 4 in the past two years.
• MLAB's largest insider holders by reported holdings are John James Sullivan (Director, 65.73K shares), Gary M. Owens (President and CEO, 64.14K shares) and John Sakys (CFO, 19.79K shares).
• The holding of John James Sullivan makes up 31.69% of all shares held by Mesa Laboratories insiders.
• Institutions held 88.47% of Mesa Laboratories' outstanding shares in their Q2 2026 13F filings, insiders about 3.67% based on their latest Form 4 filings, and other investors, including the public, the remaining 7.86%.
• In the past year, 11 insiders of Mesa Laboratories submitted 30 Form 4 filings reporting trades, awards or other transactions.
• This summary of Mesa Laboratories insider activity covers Form 4 filings through September 11, 2026.