About this page
Insider trades reported on SEC Form 4: when the people who run a company buy or sell its shares with their own money.
How to read it
- Form 4
- The form a company insider (officer, director or owner of more than 10%) must file with the SEC within two business days of buying or selling the company's shares.
- Buy (P) and Sell (S)
- Open-market purchases and sales. Gifts, option exercises and automatic tax withholding are left out because they say little about what the insider thinks.
- Value
- Shares times price, as reported on the filing.
- 10b5-1
- A trade made under a plan set up in advance. Planned sales are common and usually say less than an unplanned purchase.
- Late filing
- A Form 4 filed more than two business days after the trade.
- Vs. S&P 500
- How the stock did after the trade minus how the overall market did in the same weeks.
A real example
In January 2016, when bank stocks were falling, JPMorgan Chase CEO Jamie Dimon bought 500,000 JPMorgan shares with his own money, worth about $26 million. His Form 4 made the purchase public within days, and investors read it as a strong sign of confidence.
Explain it like I'm 13
If the coach of a team bets his own allowance that his team will win, that tells you something. A Form 4 is the note a company boss must hand in whenever he buys or sells his own company's shares, so everyone can see it.
Data from public SEC filings and congressional reports. Information, not investment advice. Check every number against the filing linked on the page.
908 Devices Inc. (MASS): Insider Trades and Fund Holdings
In the past 12 months, 908 Devices Inc. insiders reported no open-market purchases and 31 sales worth $5.61M; 23 of the sales were reported as made under a 10b5-1 trading plan.
Timeline: news and trades
Company filings (8-K), insider trades, notices of planned sales (Form 144), Congress trades and fund moves in the past year, newest first.
- Oct 7, 2026Insider saleDirector Christopher D. Brown sold $356,700 under a 10b5-1 plan
- Oct 6, 2026Insider saleCFO Joseph H. Griffith IV sold $65,150 under a 10b5-1 plan
- Oct 6, 2026Planned saleJoseph Griffith (officer) filed notice to sell about $64,000 around Oct 6, 2026
- Sep 29, 2026Insider sale10% owner Awm Investment Company, Inc. sold $207,322
- Sep 24, 2026Insider sale10% owner Awm Investment Company, Inc. sold $272,626
- Sep 23, 2026Insider sale10% owner Awm Investment Company, Inc. sold $11,250
- Sep 17, 2026Insider saleSVP John Kenneweg sold $53,727 under a 10b5-1 plan
- Sep 16, 2026Insider saleSVP John Kenneweg sold $216,344 under a 10b5-1 plan
- Sep 15, 2026Insider saleSVP John Kenneweg sold $10,000 under a 10b5-1 plan
- Sep 15, 2026Planned saleJohn Kenneweg (officer) filed notice to sell about $269,093 around Sep 15, 2026
- Sep 2, 2026Insider saleDirector Christopher D. Brown sold $317,400 under a 10b5-1 plan
- Aug 25, 2026Insider saleCFO Joseph H. Griffith IV sold $125,476 under a 10b5-1 plan
- Aug 25, 2026Planned saleJoseph Griffith (officer) filed notice to sell about $125,132 around Aug 25, 2026
- Aug 21, 2026Insider sale10% owner Awm Investment Company, Inc. sold $441,159 (10 days after: quarterly or annual results)
- Aug 20, 2026Insider sale10% owner Awm Investment Company, Inc. sold $88,638 (9 days after: quarterly or annual results)
- Aug 17, 2026Insider saleCEO Kevin J. Knopp sold $207,000 under a 10b5-1 plan (6 days after: quarterly or annual results)
- Aug 17, 2026Planned saleKevin Knopp (officer) filed notice to sell about $205,000 around Aug 17, 2026
- Aug 13, 2026Insider saleCEO Kevin J. Knopp sold $76,677 under a 10b5-1 plan (2 days after: quarterly or annual results)
- Aug 12, 2026Insider saleCEO Kevin J. Knopp sold $27,662 under a 10b5-1 plan (1 days after: quarterly or annual results)
- Aug 11, 2026NewsCompany reported: Quarterly or annual results
- Aug 11, 2026Insider saleCEO Kevin J. Knopp sold $1.4 million under a 10b5-1 plan (0 days after: quarterly or annual results)
- Aug 11, 2026Insider saleDirector Christopher D. Brown sold $77,144 under a 10b5-1 plan (0 days after: quarterly or annual results)
- Aug 11, 2026Planned saleKevin Knopp (officer) filed notice to sell about $1.3 million around Aug 11, 2026
- Aug 10, 2026Insider saleDirector Christopher D. Brown sold $85,261 under a 10b5-1 plan
- Aug 10, 2026Insider saleCEO Kevin J. Knopp sold $3,153 under a 10b5-1 plan
- Aug 10, 2026Planned saleCHRISTOPHER BROWN (director) filed notice to sell about $888,000 around Aug 10, 2026
- Aug 5, 2026Insider saleDirector Christopher D. Brown sold $169,800 under a 10b5-1 plan
- Aug 4, 2026Insider sale10% owner Awm Investment Company, Inc. sold $417,765
- Jul 2, 2026Insider saleDirector Christopher D. Brown sold $19,844 under a 10b5-1 plan
- Jul 2, 2026Insider saleCEO Kevin J. Knopp sold $2,014 under a 10b5-1 plan
- Jun 30, 2026Insider saleDirector Christopher D. Brown sold $176,800 under a 10b5-1 plan
- Jun 30, 2026FundRenaissance Technologies cut 17% in Q2 2026 (13F filed Aug 13, 2026)
- Jun 26, 2026Insider saleCEO Kevin J. Knopp sold $25,434 under a 10b5-1 plan
- Jun 25, 2026Insider saleCEO Kevin J. Knopp sold $149,131 under a 10b5-1 plan
- Jun 24, 2026Insider saleCEO Kevin J. Knopp sold $370,490 under a 10b5-1 plan
- Jun 23, 2026Insider saleDirector Christopher D. Brown sold $89,496 under a 10b5-1 plan
- Jun 23, 2026Insider saleCEO Kevin J. Knopp sold $31,003 under a 10b5-1 plan
- Jun 23, 2026Insider sale10% owner Awm Investment Company, Inc. sold $27,463
- Jun 22, 2026Insider sale10% owner Awm Investment Company, Inc. sold $41,965
Recent insider trades
Open-market purchases (code P) and sales (code S) from Form 4. Grants, option exercises and gifts are not shown. Latest filing: Oct 9, 2026.
| Filed | Insider | Type | Value |
|---|---|---|---|
| Oct 9 | Christopher D. BrownDirector | ▼ SELL10b5-1 | $357K |
| Oct 8 | Joseph H. Griffith IVCFO | ▼ SELL10b5-1 | $65K |
| Oct 1 | Awm Investment Company, Inc.10% owner | ▼ SELL | $207K |
| Sep 25 | Awm Investment Company, Inc.10% owner | ▼ SELL | $273K |
| Sep 25 | Awm Investment Company, Inc.10% owner | ▼ SELL | $11K |
| Sep 17 | John KennewegSVP | ▼ SELL10b5-1 | $216K |
| Sep 17 | John KennewegSVP | ▼ SELL10b5-1 | $54K |
| Sep 17 | John KennewegSVP | ▼ SELL10b5-1 | $10K |
| Sep 4 | Christopher D. BrownDirector | ▼ SELL10b5-1 | $317K |
| Aug 27 | Joseph H. Griffith IVCFO | ▼ SELL10b5-1 | $125K |
Insiders who traded in the past year
| Insider | Role | Buys | Bought | Sells | Sold |
|---|---|---|---|---|---|
| Christopher D. Brown | Director | 0 | $0 | 8 | $1.29M |
| Joseph H. Griffith IV | CFO | 0 | $0 | 2 | $191K |
| Awm Investment Company, Inc. | 10% owner | 0 | $0 | 8 | $1.51M |
| John Kenneweg | SVP | 0 | $0 | 3 | $280K |
| Kevin J. Knopp | CEO | 0 | $0 | 10 | $2.34M |
Buybacks and executive pay
| Year | CEO pay reported | CEO pay "actually paid" | Value of $100 invested |
|---|---|---|---|
| 2025 | $1.55M | $3.05M | n/a |
| 2024 | $1.99M | $29K | n/a |
From the company's XBRL data filed with the SEC. "Actually paid" is the SEC's pay-versus-performance measure, which counts changes in the value of stock awards. "Value of $100 invested" is the company's cumulative shareholder return as reported, usually measured from five years earlier. See all buybacks and CEO pay across companies.
A All 31 insider trades reported on time. How it is graded
Tracked funds that report MASS
From each fund's latest 13F. Holdings are as of quarter end and are filed up to 45 days later.
| Fund | Shares | Value | Change |
|---|---|---|---|
| Renaissance Technologies | 191,900 | $1.67M | ▼ −16.6% |
Reading these numbers
Insiders sell for many reasons: taxes, diversification, a house. Purchases with their own money are rarer and are usually read as more informative. A Form 4 is due within two business days of the trade. How to read a Form 4 →