908 Devices Inc.
908 Devices Inc. (MASS) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · MASS · as of Sep 30, 2025
Ownership Breakdown
108
Institutional Holders
▲ 5 vs Q2
$215.17M
Total Inst. Value
▲ $41.60M vs Q2
37.81M
Shares Outstanding
freeFloat 74.74%
24.56M
13F Shares Held
▲ 219,111 vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
MASS largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
AWM INVESTMENT COMPANY, INC. measuring & controlling devices, nec | 5.20M | 14.49% | 14.49% | $45.55B | Nov 13, 2025 | — held |
FIRST LIGHT ASSET MANAGEMENT, LLC measuring & controlling devices, nec | 2.51M | 7.00% | 7.00% | $21.99B | Nov 14, 2025 | ▲ 1.44M |
STATE STREET CORP measuring & controlling devices, nec | 2.30M | 6.41% | 6.41% | $20.14B | Nov 14, 2025 | ▲ 11.5K |
ARK INVESTMENT MANAGEMENT LLC measuring & controlling devices, nec | 1.95M | 5.45% | 5.45% | $17.12B | Nov 12, 2025 | ▼ 694.5K |
BLACKROCK, INC. measuring & controlling devices, nec | 1.76M | 4.89% | 4.89% | $15.38B | Nov 12, 2025 | ▼ 34.6K |
VANGUARD GROUP INC measuring & controlling devices, nec | 1.42M | 3.96% | 3.96% | $12.45B | Nov 7, 2025 | ▼ 9.4K |
GM ADVISORY GROUP, INC. measuring & controlling devices, nec | 678.1K | 1.89% | 1.89% | $5.94B | Nov 19, 2025 | ▼ 487.2K |
GEODE CAPITAL MANAGEMENT, LLC measuring & controlling devices, nec | 672.1K | 1.87% | 1.87% | $5.89B | Nov 12, 2025 | ▲ 13.5K |
FIRST EAGLE INVESTMENT MANAGEMENT, LLC measuring & controlling devices, nec | 604.0K | 1.68% | 1.68% | $5.29B | Nov 12, 2025 | ▲ 336.6K |
MORGAN STANLEY measuring & controlling devices, nec | 571.7K | 1.59% | 1.59% | $5.01B | May 27, 2026 | ▲ 17.4K |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
20
Increased
+2.28M shares5
New Positions
first time holders19
Decreased
−1.94M shares0
Sold Out
fully exitedNet shares change (top 50)
+343.9K
+2.28M / −1.94M
Net new holders
+6
5 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
MASS insider trading · insider activity
Source: SEC Form 4
Insiders have been primarily selling shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
7
Buy transactions
27
Sell transactions
0.26
Buy/Sell ratio
$1M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Brown Christopher D. director | Jun 4, 2026 | Sale | 100 | $9.00 | $900 | 875.5K | Form 4 ↗ |
AWM Investment Company, Inc. 10 percent owner | Jun 2, 2026 | Sale | 2,500 | $8.95 | $22.4K | 4.93M | Form 4 ↗ |
AWM Investment Company, Inc. 10 percent owner | Jun 4, 2026 | Sale | 39,782 | $8.97 | $356.9K | 4.89M | Form 4 ↗ |
Brown Christopher D. director | Jun 3, 2026 | Sale | 20,000 | $8.73 | $174.6K | 875.6K | Form 4 ↗ |
AWM Investment Company, Inc. 10 percent owner | May 27, 2026 | Sale | 1,500 | $8.25 | $12.4K | 5.12M | Form 4 ↗ |
AWM Investment Company, Inc. 10 percent owner | May 27, 2026 | Sale | 15,000 | $8.25 | $123.8K | 5.10M | Form 4 ↗ |
AWM Investment Company, Inc. 10 percent owner | May 28, 2026 | Sale | 170,442 | $8.66 | $1.48M | 4.93M | Form 4 ↗ |
Brown Christopher D. director | May 28, 2026 | Sale | 30,000 | $9.00 | $270.0K | 895.6K | Form 4 ↗ |
Griffith Joseph H. IV Chief Financial Officer | May 28, 2026 | Sale | 6,940 | $9.03 | $62.7K | 133.0K | Form 4 ↗ |
AWM Investment Company, Inc. 10 percent owner | May 11, 2026 | Sale | 5,000 | $8.25 | $41.3K | 5.12M | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
908 Devices Inc. (MASS) is primarily owned by institutional investors, who hold approximately 65.0% of total shares outstanding. Company insiders own approximately 25.26%, while retail and public investors account for the remaining 9.78%.
The largest institutional shareholder of 908 Devices Inc. is AWM INVESTMENT COMPANY, INC., holding approximately 5.20 million shares — equal to 14.49% of outstanding shares — as of September 30, 2025.
A total of 108 institutional investors currently hold MASS stock, with a combined institutional value of approximately $215,172,792 as of the most recent 13F filing period.
Frequently asked questions
MASS ownership908 Devices Inc. (MASS) is primarily owned by institutional investors, who hold approximately 65.0% of shares. The largest shareholder is AWM INVESTMENT COMPANY, INC. with a 14.49% stake. Company insiders hold 25.26%. Data sourced from SEC Form 13F as of September 30, 2025.