908 Devices Inc. (MASS) Ownership
MASS ownership summary
as of October 18, 2026- Institutions
- 83.8% of shares outstanding
- Insiders
- 7.45% of shares outstanding
- Shares outstanding
- 41.3M
- Float
- 28.1M shares available to trade
- Short interest
- 12.85% 2.7M shares short
- Days to cover
- 7.55 short interest down 0.7% vs prior month
- Institutions 83.83%
- Insiders 7.45%
- Other investors 8.72%
MASS top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | First Light Asset Management, LLC | 15.20% | 6.3M | $70.7M | +210,241 (+3.5%) | June 30, 2026 |
| 2 | Awm Investment Company Inc | 11.81% | 4.9M | $54.9M | −320,151 (−6.2%) | June 30, 2026 |
| 3 | ARK Investment Management LLC | 4.91% | 2.0M | $22.8M | +81,235 (+4.2%) | June 30, 2026 |
| 4 | BlackRock Inc | 4.70% | 1.9M | $21.9M | +176,920 (+10.0%) | June 30, 2026 |
| 5 | Arnhold & S. Bleichroeder Advisers, LLC | 4.50% | 1.9M | $20.9M | +1.1M (+131.5%) | June 30, 2026 |
| 6 | Needham Investment Management, LLC | 4.40% | 1.8M | $20.5M | +580,620 (+46.8%) | June 30, 2026 |
| 7 | Vanguard Capital Management, LLC | 3.12% | 1.3M | $14.5M | +172,334 (+15.4%) | June 30, 2026 |
| 8 | Geode Capital Management, LLC | 1.84% | 762K | $8.6M | +66,342 (+9.5%) | June 30, 2026 |
| 9 | Granahan Investment Management Inc.. | 1.67% | 692K | $7.8M | −2,978 (−0.4%) | June 30, 2026 |
| 10 | State Street Corp | 1.47% | 607K | $6.8M | −19,332 (−3.1%) | June 30, 2026 |
| 11 | Essex Investment Management Company, LLC | 1.14% | 470K | $5.3M | −20,977 (−4.3%) | June 30, 2026 |
| 12 | Morgan Stanley - Brokerage Accounts | 0.98% | 404K | $4.5M | +30,820 (+8.3%) | June 30, 2026 |
| 13 | Prescott Group Capital Management LLC | 0.87% | 362K | $4.1M | — | June 30, 2026 |
| 14 | Meros Investment Management, LP | 0.87% | 361K | $4.1M | −370 (−0.1%) | June 30, 2026 |
| 15 | American Century Companies Inc | 0.87% | 360K | $4.1M | +303,954 (+543.8%) | June 30, 2026 |
| 16 | Northern Trust Corp | 0.64% | 266K | $3.0M | +25,085 (+10.4%) | June 30, 2026 |
| 17 | Bank of America Corp | 0.61% | 251K | $2.8M | +225,949 (+901.0%) | June 30, 2026 |
| 18 | Gm Advisory Group Inc | 0.58% | 238K | $2.7M | −40,574 (−14.6%) | March 31, 2026 |
| 19 | Charles Schwab Investment Management Inc | 0.57% | 234K | $2.6M | +4,403 (+1.9%) | June 30, 2026 |
| 20 | Amova Asset Management Americas, Inc | 0.55% | 229K | $2.6M | −41,192 (−15.3%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 12 holders added 2.9M shares and 7 cut 446K.
MASS top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | ARK Genomic Revolution ETF | 4.67% | 1.9M | $21.7M | +4,722 (+0.2%) | September 30, 2026 |
| 2 | Needham Aggressive Growth Retail | 3.38% | 1.4M | $15.7M | +447,650 (+47.1%) | June 30, 2026 |
| 3 | Avantis US Small Cap Value ETF | 2.26% | 935K | $10.5M | +7,272 (+0.8%) | September 30, 2026 |
| 4 | Vanguard MStar Total Stk Mkt Idx Invest | 2.23% | 920K | $10.4M | — | August 31, 2026 |
| 5 | First Eagle Small Cap Opportunity I | 2.07% | 854K | $9.6M | −7,103 (−0.8%) | August 31, 2026 |
| 6 | iShares Russell 2000 ETF | 1.96% | 808K | $9.1M | −9,344 (−1.1%) | September 30, 2026 |
| 7 | Fidelity Small Cap Index | 0.77% | 317K | $3.6M | +1,435 (+0.5%) | July 31, 2026 |
| 8 | iShares Russell 2000 Value ETF | 0.71% | 294K | $3.3M | +446 (+0.2%) | September 30, 2026 |
| 9 | Needham Small Cap Growth Retail | 0.61% | 253K | $2.8M | +132,970 (+110.8%) | June 30, 2026 |
| 10 | Schwab US Small-Cap ETF™ | 0.42% | 175K | $2.0M | +117 (+0.1%) | September 30, 2026 |
| 11 | Vanguard Russell 2000 ETF | 0.40% | 167K | $1.9M | +3,360 (+2.1%) | August 31, 2026 |
| 12 | Victory Small Cap Stock | 0.37% | 155K | $1.7M | +11,191 (+7.8%) | June 30, 2026 |
| 13 | Fidelity Extended Market Index | 0.34% | 139K | $1.6M | −748 (−0.5%) | August 31, 2026 |
| 14 | ARK Genomic Revolution ETF A USD Acc | 0.29% | 119K | $1.3M | — | September 30, 2026 |
| 15 | 1290 Essex Small Cap Growth I | 0.27% | 114K | $1.3M | — | August 31, 2026 |
| 16 | Acuitas US Microcap Institutional | 0.24% | 101K | $1.1M | −28,913 (−22.3%) | June 30, 2026 |
| 17 | iShares Micro-Cap ETF | 0.24% | 99K | $1.1M | −686 (−0.7%) | September 30, 2026 |
| 18 | Stt Strt® SPDR® S&PKenshoFutSecETF | 0.21% | 87K | $982,165 | — | September 30, 2026 |
| 19 | First Eagle US Small Cap Opp I-UC | 0.19% | 79K | $885,194 | — | August 31, 2026 |
| 20 | Schwab Small Cap Index | 0.17% | 72K | $808,558 | — | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
MASS insider transactions
latest 15| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-04-10 | Christopher D Brown | Sell | $7.07 | 17,578 | $124,276 |
| 2026-04-10 | Kevin J Mccallion | Sell | $7.01 | 2,693 | $18,878 |
| 2026-04-09 | Christopher D Brown | Sell | $7.04 | 7,392 | $52,040 |
| 2026-04-09 | Kevin J Mccallion | Sell | $7.03 | 5,420 | $38,103 |
| 2026-04-08 | Christopher D Brown | Sell | $7.05 | 15,030 | $105,962 |
| 2026-04-08 | Kevin J Mccallion | Sell | $7.05 | 18,580 | $130,989 |
| 2026-02-02 | Joseph H Iv Griffith | Sell | $6.18 | 23,175 | $143,222 |
| 2025-10-03 | Joseph H Iv Griffith | Sell | $9.05 | 4,292 | $38,843 |
| 2025-10-02 | Joseph H Iv Griffith | Sell | $9.04 | 708 | $6,400 |
| 2025-09-19 | Joseph H Iv Griffith | Sell | $7.07 | 5,000 | $35,350 |
| 2025-06-18 | Michael S. Turner | Sell | $7.50 | 1,373 | $10,298 |
| 2025-06-17 | Michael S Turner | Sell | $7.51 | 7,148 | $53,681 |
| 2025-06-16 | Michael S Turner | Sell | $7.51 | 16,082 | $120,776 |
| 2025-06-04 | Joseph H Iv Griffith | Sell | $7.08 | 6,940 | $49,135 |
| 2025-05-14 | Mark Spoto | Buy | $4.29 | 10,000 | $42,900 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
MASS shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns MASS
Institutional investors own 83.8% of 908 Devices's shares and insiders 7.45%. The largest holder is First Light Asset Management, LLC with 15.20% of the shares (6.3M), as of June 30, 2026. Among the top 20 institutions, 12 added shares and 7 reduced their stake in the latest filings. Short interest is 12.85% of the float, or 7.55 days of average trading volume. The share count rose 460.6% since 2019.
Related: MASS analyst forecast, MASS key metrics. See the MASS stock overview for the latest quote and news.
MASS ownership FAQ
Who owns the most 908 Devices stock?
The largest shareholders of 908 Devices are First Light Asset Management, LLC (15.20%), Awm Investment Company Inc (11.81%), ARK Investment Management LLC (4.91%), BlackRock Inc (4.70%), Arnhold & S. Bleichroeder Advisers, LLC (4.50%).
What percentage of 908 Devices is owned by institutions?
Institutions hold 83.8% of 908 Devices's shares outstanding; insiders hold 7.45%.
Which funds own 908 Devices?
The largest fund holders of 908 Devices are ARK Genomic Revolution ETF (4.67%), Needham Aggressive Growth Retail (3.38%), Avantis US Small Cap Value ETF (2.26%), Vanguard MStar Total Stk Mkt Idx Invest (2.23%), First Eagle Small Cap Opportunity I (2.07%).
What is 908 Devices's short interest?
2.7M shares of 908 Devices were sold short, 12.85% of the float; at the average daily volume it would take 7.55 days to cover.
Are insiders buying or selling 908 Devices?
Of the latest 15 reported insider transactions in 908 Devices (since May 14, 2025), 1 were purchases and 14 were sales.
How many shares of 908 Devices are outstanding?
908 Devices has 41.3M shares outstanding, of which 28.1M are in the public float.