SEC Form 4
Mesa Laboratories Inc (MLAB) insider trading
In the 12 months to Oct 26, 2026, 2 MLAB insiders reported open-market sales of $1.1M across 3 filings; 4 insiders bought $1.4M.
Latest filing · Last 12 months · Source: SEC EDGAR · How we count
- Open-market sales
- $1.1M
- 3 filings · 2 insiders
- Open-market purchases
- $1.4M
- 5 filings
- Pre-arranged sales (10b5-1)
- 1 of 3
- $116.6K of $1.1M sold (10%)
Who traded MLAB, and when
- Purchase
- Sale
MLAB daily close from Oct 27, 2025 to Oct 26, 2026, between $70.60 and $142.23, last $130.45. 3 sale and 5 purchase filings by 6 insiders, marked at their filing dates. John James Sullivan, Director: sold $800.1K across 1 filing, first filed Aug 17, 2026, last Aug 17, 2026. Siddhartha Kadia, President and CEO: bought $800.1K across 1 filing, first filed Aug 17, 2026, last Aug 17, 2026. Brian David Archbold, SVP Operations: sold $341.7K across 2 filings, first filed Jun 17, 2026, last Jun 23, 2026. Shiraz Shabanali Ladiwala, Director: bought $252.8K across 1 filing, first filed Mar 10, 2026, last Mar 10, 2026. R. Tony Tripeny, Director: bought $202.3K across 2 filings, first filed Mar 10, 2026, last Aug 17, 2026. Mark Christopher Capone, Director: bought $99.3K across 1 filing, first filed Mar 10, 2026, last Mar 10, 2026.
Largest mark · tap a row for others
John James Sullivan · Director
Sale $800,090
7,093 shares at $112.80 avg
Filed Aug 17, 2026 · traded Aug 13
Close on filing date $107.64
John James Sullivan · Director
Director
$800.1K soldSiddhartha Kadia · President and CEO
President and CEO
$800.1K boughtBrian David Archbold · SVP Operations
SVP Operations
$341.7K soldShiraz Shabanali Ladiwala · Director
Director
$252.8K boughtR. Tony Tripeny · Director
Director
$202.3K boughtMark Christopher Capone · Director
Director
$99.3K boughtOpen-market trades
8 filings in the last 12 months| Insider | Role | Sold | Bought | Filings | Pre-arranged (10b5-1) | Last filed |
|---|---|---|---|---|---|---|
| John James Sullivan | Director | $800.1K | — | 1 | — | |
| Siddhartha Kadia | President and CEO | — | $800.1K | 1 | — | |
| Brian David Archbold | SVP Operations | $341.7K | — | 2 | 34% of sales | |
| Shiraz Shabanali Ladiwala | Director | — | $252.8K | 1 | — | |
| R. Tony Tripeny | Director | — | $202.3K | 2 | — | |
| Mark Christopher Capone | Director | — | $99.3K | 1 | — |
| Filed | Insider | Type | Shares | Avg price | Value | Held after | Source |
|---|---|---|---|---|---|---|---|
traded | R. Tony Tripeny Director | Purchase | 900 | $113.69 | $102.3K | 6,298 | |
traded | Siddhartha Kadia President and CEO | Purchase | 7,093 | $112.80 | $800.1K | 7,093 | |
traded | John James Sullivan Director | Sale | 7,093 | $112.80 | $800.1K | 17,834 | |
traded | Brian David Archbold SVP Operations | Sale | 2,516 | $89.50 | $225.2K | 6,377 | |
traded | Brian David Archbold SVP Operations | SalePre-arranged (10b5-1) | 1,151 | $101.27 | $116.6K | 3,710 | |
traded | R. Tony Tripeny Director | Purchase | 1,315 | $76.00 | $99.9K | 5,398 | |
traded | Mark Christopher Capone Director | Purchase | 1,301 | $76.35 | $99.3K | 3,429 | |
traded | Shiraz Shabanali Ladiwala Director | Purchase | 3,500 | $72.23 | $252.8K | 8,523 |
GET /stocks/filings/vX/form-4?tickers=MLAB&filing_date.gte=2025-10-26&sort=filing_date.desc&limit=500{
"status": "OK",
"results": [
{
"tickers": [
"MLAB"
],
"issuer_cik": "0000724004",
"owner_cik": "0001305784",
"accession_number": "0000724004-26-000085",
"form_type": "4",
"filing_date": "2026-08-17",
"period_of_report": "2026-08-13",
"issuer_name": "MESA LABORATORIES INC /CO/",
"issuer_trading_symbol": "MLAB",
"owner_name": "Sullivan John James",
"is_director": true,
"is_officer": false,
"is_ten_percent_owner": false,
"is_other": false,
"security_type": "non_derivative",
"record_type": "transaction",
"security_title": "Common Stock",
"transaction_timeliness": "O",
"aff_10b5_one": false,
"transaction_date": "2026-08-13",
"transaction_code": "S",
"equity_swap_involved": false,
"transaction_shares": 7093,
"transaction_price_per_share": 112.8,
"transaction_acquired_disposed": "D",
"shares_owned_following_transaction": 17834,
"transaction_value": 800090.4,
"not_subject_to_section_16": false,
"direct_or_indirect": "D",
"footnotes": [
{
"id": "F1",
"description": "Represents shares sold directly in a private transaction to Siddhartha Kadia, Mesa President and CEO"
}
]
},
{
"tickers": [
"MLAB"
],
"issuer_cik": "0000724004",
"owner_cik": "0001573666",
"accession_number": "0000724004-26-000084",
"form_type": "4",
"filing_date": "2026-08-17",
"period_of_report": "2026-08-13",
"issuer_name": "MESA LABORATORIES INC /CO/",
"issuer_trading_symbol": "MLAB",
"owner_name": "Kadia Siddhartha",
"is_director": false,
"is_officer": true,
"is_ten_percent_owner": false,
"is_other": false,
"officer_title": "President and CEO",
"security_type": "non_derivative",
"record_type": "transaction",
"security_title": "Common Stock",
"transaction_timeliness": "O",
"aff_10b5_one": false,
"transaction_date": "2026-08-13",
"transaction_code": "P",
"equity_swap_involved": false,
"transaction_shares": 7093,
"transaction_price_per_share": 112.8,
"transaction_acquired_disposed": "A",
"shares_owned_following_transaction": 7093,
"transaction_value": 800090.4,
"not_subject_to_section_16": false,
"direct_or_indirect": "I",
"nature_of_ownership": "By Trust",
"footnotes": [
{
"id": "F1",
"description": "Represents shares purchased directly in a private transaction from John Sullivan, Mesa Board Chair by the Anjou Parekh Lifetime Access Trust for which the reporting person's spouse serves as trustee."
},
{
"id": "F2",
"description": "Represents shares held by the Anjou Parekh Lifetime Access Trust for which the reporting person's spouse serves as trustee. The reporting person disclaims beneficial ownership of the securities held by the trust except to the extent of his pecuniary interest therein."
}
]
}
]
}
// trimmed to 2 resultsThe response includes every Form 4 record; this page keeps open-market purchases and sales on common stock and removes duplicate joint-filer rows.
Other insider activity (not market trades) · 24 records
- Option exercises16 records
- Tax withholding (sold to cover)4 records
- Grants and awards3 records
- Gifts1 record
Reported on Form 4 but not purchases or sales in the market, so not counted in the totals above.
How to read this page
- Open-market purchase or sale
- A buy or sell of the company's stock at market price. Grants, option exercises, shares withheld for tax, gifts and employee stock plan purchases are listed separately and not counted.
- Pre-arranged (10b5-1)
- The insider marked the filing as made under a trading plan set up in advance (SEC Rule 10b5-1). The mark covers the whole filing, and an unmarked filing may still be under a plan.
- Filing date
- Insiders have two business days to report a trade. Totals and the chart use the filing date, when the trade became public.
Frequently asked questions
Has Mesa Laboratories Inc's CEO sold stock?
No. Siddhartha Kadia and Gary M. Owens (CEOs) made no open-market sales filed as CEO in the last 12 months.
How current is MLAB’s insider data?
These are MLAB Form 4 filings from the last year, refreshed daily. The Massive Form 4 API has the full, continuously updated record.
What counts as an open-market buy or sell?
Only purchases and sales at the market price. Option exercises, grants, gifts, and shares withheld for taxes are reported on Form 4 but are left out of the buy and sell totals.
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This page joins two Massive endpoints: Form 4 filings and daily prices. Ask an agent to watch for new filings:
Using the Massive API (massive.com/docs/llms.txt), check Form 4 filings for MLAB every day with transaction_code=P and tell me when an insider files an open-market purchase, with their role, shares, price and the filing link.
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