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sellWeak cluster of 310b5-1 plan

Christopher D. Brown sold $162k of MASS

Chief Product Officer at 908 Devices Inc.. 17,800 shares at an average of $9.12, traded Aug 10, 2026, filed Aug 12, 2026.

Warning score
21
Value
$162k
17,800 shares
Holdings after
805,559
-2% from before
From 52-week low
+73%
low $5.09, close $8.80
From 52-week high
-4%
high $9.15, as of Aug 10, 2026

Score components

  • Role
    Director
    +15
  • Trade size
    $162k at market
    +11
  • Share of holdings sold
    Sold 2.2% of holdings
    0
  • Cluster
    3 insiders selling within 14 days
    +15
  • 10b5-1 plan
    Pre-scheduled under a 10b5-1 plan
    -20

What happened after comparable sells

Same side and tier, against the S&P 500, at 1, 3 and 6 months. Shown to Pro users; the whole table is on the backtest page.

Price around the trade, and since

From a quarter before the trade to today. The arrow is the trade, the circle the day the filing reached EDGAR, which is the first day anyone outside could act; the dotted line is the S&P 500 rebased to that day's close.

MASSOct 12, 2026 · close 11.82
Since filing Aug 12, 2026: +18.0%SPY +1.0% · excess +17.0%

Daily candles, adjusted for splits and dividends. Green arrows are insider buys, red are sells, sized by value; the dashed line is the close on the filing day, the dotted line SPY rebased to it.Charts by TradingView Lightweight Charts™

Rows in this filing

Every transaction in Form 4 0001836988-26-000023, as filed. Open on EDGAR

DateTransactionSharesPriceValueHoldings afterFiled
Aug 10, 2026SOpen-market sale
Common Stock10b5-1
-9,442$9.03$85k813,917Aug 12, 2026
Aug 11, 2026SOpen-market sale
Common Stock10b5-1
-8,358$9.23$77k805,559Aug 12, 2026

Related signals

Other insiders at 908 Devices Inc. and this insider’s other filings.

ScoreCompanyInsiderValueHoldingsFiled
Pro nowfree Oct 16, 2026
MASSsell 310b5-1
908 Devices Inc.
Christopher D. Brown
Chief Product Officer
$357k
30,000 shares
-4%
Pro nowfree Oct 15, 2026
MASSsell 310b5-1
908 Devices Inc.
Joseph H. Griffith IV
Chief Financial Officer
$65k
5,000 shares
-4%
39Weak
MASSsell 4
908 Devices Inc.
AWM Investment Company, Inc.
owner
$207k
18,000 shares
-0%
41Moderate
MASSsell 4
908 Devices Inc.
AWM Investment Company, Inc.
owner
$284k
25,000 shares
-1%
19Weak
MASSsell 310b5-1
908 Devices Inc.
John Kenneweg
SVP, Sales & Product Marketing
$280k
27,656 shares
-47%
24Weak
MASSsell 410b5-1
908 Devices Inc.
Christopher D. Brown
Chief Product Officer
$317k
30,000 shares
-4%
28Weak
MASSsell 410b5-1
908 Devices Inc.
Joseph H. Griffith IV
Chief Financial Officer
$125k
11,459 shares
-9%
45Moderate
MASSsell 4
908 Devices Inc.
AWM Investment Company, Inc.
owner
$530k
50,000 shares
-1%
34Weak
MASSsell 410b5-1
908 Devices Inc.
Kevin J. Knopp
President and CEO
$284k
27,622 shares
-5%
50Moderate
MASSsell 310b5-1
908 Devices Inc.
Kevin J. Knopp
President and CEO
$1.5M
149,013 shares
-20%

Not investment advice. Scores and forward returns are decision support built from public SEC filings and past prices; they describe what happened after comparable filings, not what will happen after this one. Do your own research and size your risk.

Christopher D. Brown sold $162k of MASS | InsiderTell