SEC Form 4
908 Devices Inc. (MASS) insider trading
In the 12 months to Oct 26, 2026, 6 MASS insiders reported open-market sales of $9.5M across 34 filings; no open-market purchases were filed.
Latest filing · Last 12 months · Source: SEC EDGAR · How we count
- Open-market sales
- $9.5M
- 34 filings · 6 insiders
- Open-market purchases
- $0
- 0 filings
- Pre-arranged sales (10b5-1)
- 24 of 34
- $5.2M of $9.5M sold (55%)
Who traded MASS, and when
- Sale
- Sale, pre-arranged (10b5-1)
MASS daily close from Oct 27, 2025 to Oct 26, 2026, between $5.09 and $12.80, last $11.77. 34 sale and 0 purchase filings by 6 insiders, marked at their filing dates. AWM Investment Company, Inc., 10% owner: sold $4.2M across 9 filings, first filed May 8, 2026, last Oct 1, 2026. Kevin J. Knopp, President and CEO: sold $2.3M across 5 filings, first filed Jun 25, 2026, last Aug 17, 2026. Christopher D. Brown, Director: sold $2.2M across 12 filings, first filed Apr 10, 2026, last Oct 9, 2026. John Kenneweg, SVP, Sales & Product Marketing: sold $428.1K across 2 filings, first filed May 11, 2026, last Sep 17, 2026. Joseph H. Griffith IV, Chief Financial Officer: sold $253.3K across 3 filings, first filed May 29, 2026, last Oct 8, 2026. Kevin J. McCallion, SVP, Products and Production: sold $188.0K across 3 filings, first filed Mar 5, 2026, last Apr 14, 2026.
Largest mark · tap a row for others
AWM Investment Company, Inc. · 10% owner
Filing 1 of 2 within a week · $1,991,322 total
Sale $1,612,091
186,942 shares at $8.62 avg
Filed May 29, 2026 · traded May 27
Close on filing date $8.41
AWM Investment Company, Inc. · 10% owner
10% owner
$4.2M soldKevin J. Knopp · President and CEO
President and CEO
$2.3M soldChristopher D. Brown · Director
Director
$2.2M soldJohn Kenneweg · SVP, Sales & Product Marketing
SVP, Sales & Product Marketing
$428.1K soldJoseph H. Griffith IV · Chief Financial Officer
Chief Financial Officer
$253.3K soldKevin J. McCallion · SVP, Products and Production
SVP, Products and Production
$188.0K soldOpen-market trades
34 filings in the last 12 months| Insider | Role | Sold | Bought | Filings | Pre-arranged (10b5-1) | Last filed |
|---|---|---|---|---|---|---|
| AWM Investment Company, Inc. | 10% owner | $4.2M | — | 9 | — | |
| Kevin J. Knopp | President and CEO | $2.3M | — | 5 | 100% of sales | |
| Christopher D. Brown | Director | $2.2M | — | 12 | 100% of sales | |
| John Kenneweg | SVP, Sales & Product Marketing | $428.1K | — | 2 | 65% of sales | |
| Joseph H. Griffith IV | Chief Financial Officer | $253.3K | — | 3 | 100% of sales | |
| Kevin J. McCallion | SVP, Products and Production | $188.0K | — | 3 | 100% of sales |
| Filed | Insider | Type | Shares | Avg price | Value | Held after | Source |
|---|---|---|---|---|---|---|---|
traded | Christopher D. Brown Director | SalePre-arranged (10b5-1) | 30,000 | $11.89 | $356.7K | 745,559 | |
traded | Joseph H. Griffith IV Chief Financial Officer | SalePre-arranged (10b5-1) | 5,000 | $13.03 | $65.2K | 116,497 | |
traded | AWM Investment Company, Inc. 10% owner | Sale | 18,000 | $11.52 | $207.3K | 4,736,773 | |
traded | AWM Investment Company, Inc. 10% owner | Sale | 25,000 | $11.36 | $283.9K | Multiple accounts | |
traded | John Kenneweg SVP, Sales & Product Marketing | SalePre-arranged (10b5-1) | 27,656 | $10.13 | $280.1K | 57,784 | |
traded | Christopher D. Brown Director | SalePre-arranged (10b5-1) | 30,000 | $10.58 | $317.4K | 775,559 | |
traded | Joseph H. Griffith IV Chief Financial Officer | SalePre-arranged (10b5-1) | 11,459 | $10.95 | $125.5K | 121,497 | |
traded | AWM Investment Company, Inc. 10% owner | Sale | 50,000 | $10.60 | $529.8K | 4,779,773 | |
traded | Kevin J. Knopp President and CEO | SalePre-arranged (10b5-1) | 27,622 | $10.27 | $283.7K | 555,968 | |
traded | Kevin J. Knopp President and CEO | SalePre-arranged (10b5-1) | 149,013 | $9.90 | $1.5M | 583,590 | |
traded | Christopher D. Brown Director | SalePre-arranged (10b5-1) | 17,800 | $9.12 | $162.4K | 805,559 | |
traded | Christopher D. Brown Director | SalePre-arranged (10b5-1) | 20,000 | $8.49 | $169.8K | 823,359 | |
traded | AWM Investment Company, Inc. 10% owner | Sale | 50,000 | $8.36 | $417.8K | 4,829,773 | |
traded | Kevin J. Knopp President and CEO | SalePre-arranged (10b5-1) | 222 | $9.07 | $2.0K | 732,603 | |
traded | Christopher D. Brown Director | SalePre-arranged (10b5-1) | 2,200 | $9.02 | $19.8K | 843,359 | |
traded | Christopher D. Brown Director | SalePre-arranged (10b5-1) | 20,000 | $8.84 | $176.8K | 845,559 | |
traded | Kevin J. Knopp President and CEO | SalePre-arranged (10b5-1) | 2,798 | $9.09 | $25.4K | 732,825 | |
traded | Kevin J. Knopp President and CEO | SalePre-arranged (10b5-1) | 60,345 | $9.12 | $550.6K | 735,623 | |
traded | Christopher D. Brown Director | SalePre-arranged (10b5-1) | 9,900 | $9.04 | $89.5K | 865,559 | |
traded | AWM Investment Company, Inc. 10% owner | Sale | 7,718 | $9.00 | $69.4K | 4,879,773 | |
traded | Christopher D. Brown Director | SalePre-arranged (10b5-1) | 100 | $9.00 | $900 | 875,459 | |
traded | AWM Investment Company, Inc. 10% owner | Sale | 42,282 | $8.97 | $379.2K | 4,887,491 | |
traded | Christopher D. Brown Director | SalePre-arranged (10b5-1) | 20,000 | $8.73 | $174.6K | 875,559 | |
traded | Joseph H. Griffith IV Chief Financial Officer | SalePre-arranged (10b5-1) | 6,940 | $9.03 | $62.7K | 132,956 | |
traded | AWM Investment Company, Inc. 10% owner | Sale | 186,942 | $8.62 | $1.6M | 4,929,773 | |
traded | Christopher D. Brown Director | SalePre-arranged (10b5-1) | 30,000 | $9.00 | $270.0K | 895,559 | |
traded | AWM Investment Company, Inc. 10% owner | Sale | 5,000 | $8.25 | $41.3K | 5,116,715 | |
traded | John Kenneweg SVP, Sales & Product Marketing | Sale | 18,255 | $8.11 | $148.0K | 57,784 | |
traded | AWM Investment Company, Inc. 10% owner | Sale | 78,209 | $8.08 | $632.1K | 5,121,715 | |
traded | Christopher D. Brown Director | SalePre-arranged (10b5-1) | 20,000 | $7.23 | $144.6K | 925,559 | |
traded | Kevin J. McCallion SVP, Products and Production | SalePre-arranged (10b5-1) | 2,693 | $7.01 | $18.9K | 44,925 | |
traded | Christopher D. Brown Director | SalePre-arranged (10b5-1) | 40,000 | $7.06 | $282.3K | 945,559 | |
traded | Kevin J. McCallion SVP, Products and Production | SalePre-arranged (10b5-1) | 24,000 | $7.05 | $169.1K | 44,925 | |
traded | Kevin J. McCallion SVP, Products and Production | SalePre-arranged (10b5-1) | 7 | $7.00 | $49 | 44,925 |
GET /stocks/filings/vX/form-4?tickers=MASS&filing_date.gte=2025-10-26&sort=filing_date.desc&limit=500{
"status": "OK",
"results": [
{
"tickers": [
"MASS"
],
"issuer_cik": "0001555279",
"owner_cik": "0001836988",
"accession_number": "0001836988-26-000027",
"form_type": "4",
"filing_date": "2026-10-09",
"period_of_report": "2026-10-07",
"issuer_name": "908 Devices Inc.",
"issuer_trading_symbol": "MASS",
"owner_name": "Brown Christopher D.",
"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": true,
"transaction_date": "2026-10-07",
"transaction_code": "S",
"equity_swap_involved": false,
"transaction_shares": 30000,
"transaction_price_per_share": 11.89,
"transaction_acquired_disposed": "D",
"shares_owned_following_transaction": 745559,
"transaction_value": 356700,
"direct_or_indirect": "D",
"footnotes": [
{
"id": "F1",
"description": "This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 24, 2025."
},
{
"id": "F2",
"description": "The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $11.75 to $12.12 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote."
}
]
},
{
"tickers": [
"MASS"
],
"issuer_cik": "0001555279",
"owner_cik": "0001431531",
"accession_number": "0001431531-26-000009",
"form_type": "4",
"filing_date": "2026-10-08",
"period_of_report": "2026-10-06",
"issuer_name": "908 Devices Inc.",
"issuer_trading_symbol": "MASS",
"owner_name": "Griffith Joseph H. IV",
"is_director": false,
"is_officer": true,
"is_ten_percent_owner": false,
"is_other": false,
"officer_title": "Chief Financial Officer",
"security_type": "non_derivative",
"record_type": "transaction",
"security_title": "Common Stock",
"transaction_timeliness": "O",
"aff_10b5_one": true,
"transaction_date": "2026-10-06",
"transaction_code": "S",
"equity_swap_involved": false,
"transaction_shares": 5000,
"transaction_price_per_share": 13.03,
"transaction_acquired_disposed": "D",
"shares_owned_following_transaction": 116497,
"transaction_value": 65150,
"direct_or_indirect": "D",
"footnotes": [
{
"id": "F1",
"description": "This transaction was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 26, 2026."
}
]
}
]
}
// 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) · 34 records
- Option exercises28 records
- Tax withholding (sold to cover)3 records
- Gifts2 records
- Other1 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.
- Counted once
- When several owners (a fund and its partners, say) report the same trade, it's counted once. Corrected filings replace the originals.
Frequently asked questions
Has 908 Devices Inc.'s CEO sold stock?
Yes. Kevin J. Knopp (CEO) sold 240,000 shares ($2.3M) between Jun 2026 and Aug 2026, all under a pre-arranged 10b5-1 plan.
How current is MASS’s insider data?
These are MASS 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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