MASS · 908 Devices Inc. · Shareholders & Ownership

$11.80 +0.29 (+2.48%)

Russell 2000 member Rebalance outlook locked

Market Cap

$475.75M

41.33M

Volume · Oct 21 410.54K Avg daily vol (3M) 418.84K

Every disclosed holder of MASS in one list: 13F institutions, Schedule 13D and 13G filers, insiders (Forms 3, 4 and 5) and registered funds, each from its own latest filing. Holders nest by CIK and SEC reporting links, never by name, and each is summed once.

How the holder list picks a filing →

Who Owns MASS

13F quarter Sep 30, 2026, combined view: filers that have not filed yet carry their Jun 30, 2026 positions

No chart: the summed disclosures exceed shares outstanding, so they are not parts of one whole.

Holder group	Holders	Shares	% Out	Summed
Institutional (13F)	111	28,055,796	67.88%	Yes
Insiders (Forms 3, 4, 5)	14	8,644,467	20.91%	Yes
13D/G-only blocks	4	8,483,682	20.52%	Yes
Remaining	—	3,850,240	-9.32%	Negative
Registered funds (N-PORT, not summed)	117	9,208,166	22.28%	No

Shares outstanding: 41,333,705, the issuer's latest cover-page count restated onto today's split basis.

Remaining is negative: the summed disclosures exceed shares outstanding, as when filings are dated at different times or holders that do not disclose their links count the same shares. It is flagged, not clipped.

13D/G-only counts each filer's latest 13D or 13G that no 13F report of the listing contains, that names no 13F filer and that no counted insider files. Funds are never summed: their shares sit inside their advisers' 13F reports.

Holders of MASS

One row per holder Every filing By ultimate parent

All 13F Funds Insiders 13D/G Non-US

#	Holder	Shares	% Out	Change	As of	Notes
1	First Light Asset Management, LLC 13F CIK 1600004 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	6,282,804	15.20%	+210,241	Jun 30, 2026	carried, not yet filed for the newest quarter
2	Keith Crandell 13G CIK 1402439 · Unknown · Jun 30, 2026 Rule 13d-1(d), exempt investor	5,824,877	14.09%	+15,661	Jun 30, 2026	Rule 13d-1(d), exempt investor
3	CRANDELL KEITH Insider CIK 1219039 · Jun 10, 2026 10% Owner, issuer-wide	5,764,419	13.95%	+14,083	Jun 10, 2026	10% Owner, issuer-wide
4	AWM Investment Company, Inc. Insider CIK 1535264 · Sep 29, 2026 10% Owner, issuer-wide, not summed	4,736,773	11.46%	—	Sep 29, 2026	10% Owner, issuer-wide, not summed
4.1	AWM Investment Company, Inc. 13F CIK 1535264 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	4,879,773	11.81%	-320,151	Jun 30, 2026	carried, not yet filed for the newest quarter
4.2	AWM Investment Company, Inc. 13G CIK 1535264 · Registered investment adviser · Jun 30, 2026 Rule 13d-1(b), qualified institution, not summed	4,879,773	11.81%	-320,151	Jun 30, 2026	Rule 13d-1(b), qualified institution, not summed
5	ARK Investment Management LLC 13F CIK 1697748 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	2,027,920	4.91%	+81,235	Jun 30, 2026	carried, not yet filed for the newest quarter
5.1	ARK Investment Management LLC 13G CIK 1697748 · Registered investment adviser · Jun 30, 2026 Rule 13d-1(b), qualified institution, not summed	2,027,920	4.91%	+144,714	Jun 30, 2026	Rule 13d-1(b), qualified institution, not summed
5.2	ARK Genomic Revolution ETF Fund S000042975 · Registered fund · Jul 31, 2026 ARK ETF Trust, not summed	1,905,332	4.61%	-47,220	Jul 31, 2026	ARK ETF Trust, not summed
6	BlackRock, Inc. 13F CIK 2012383 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	1,944,236	4.70%	+176,920	Jun 30, 2026	carried, not yet filed for the newest quarter
6.1	BlackRock, Inc. 13G CIK 2012383 · Holding company · Jun 30, 2026 Rule 13d-1(b), qualified institution, not summed	1,940,690	4.70%	+326,676	Jun 30, 2026	Rule 13d-1(b), qualified institution, not summed
6.2	iShares Russell 2000 ETF Fund S000004344 · Registered fund · Jun 30, 2026 iShares Trust, not summed	757,244	1.83%	+57,870	Jun 30, 2026	iShares Trust, not summed
6.3	iShares Russell 2000 Value ETF Fund S000004342 · Registered fund · Jun 30, 2026 iShares Trust, not summed	261,667	0.63%	+207,771	Jun 30, 2026	iShares Trust, not summed
6.4	iShares Micro-Cap ETF Fund S000004439 · Registered fund · Jun 30, 2026 iShares Trust, not summed	97,794	0.24%	+27,984	Jun 30, 2026	iShares Trust, not summed
6.5	Master Small Cap Index Series Fund S000002716 · Registered fund · Jun 30, 2026 Quantitative Master Series LLC, not summed	53,796	0.13%	+13,429	Jun 30, 2026	Quantitative Master Series LLC, not summed
7	NEEDHAM INVESTMENT MANAGEMENT LLC 13F CIK 1167212 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	1,820,620	4.40%	+580,620	Jun 30, 2026	carried, not yet filed for the newest quarter
7.1	Needham Aggressive Growth Fund Fund S000003815 · Registered fund · Jun 30, 2026 Needham Funds Inc, not summed	1,397,650	3.38%	+472,650	Jun 30, 2026	Needham Funds Inc, not summed
7.2	Needham Small Cap Growth Fund Fund S000003816 · Registered fund · Jun 30, 2026 Needham Funds Inc, not summed	252,970	0.61%	+132,970	Jun 30, 2026	Needham Funds Inc, not summed
8	EVENTIDE ASSET MANAGEMENT, LLC 13G CIK 1442891 · Registered investment adviser · Dec 31, 2023 Rule 13d-1(b), qualified institution	1,430,995	3.46%	—	Dec 31, 2023	Rule 13d-1(b), qualified institution
9	VANGUARD CAPITAL MANAGEMENT LLC 13F CIK 2100119 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	1,291,570	3.12%	+172,334	Jun 30, 2026	carried, not yet filed for the newest quarter
10	Alger Associates, Inc. 13-3017981 13G CIK 1000264 · Holding company · Oct 31, 2023 Rule 13d-1(b), qualified institution	1,227,494	2.97%	—	Oct 31, 2023	Rule 13d-1(b), qualified institution
11	Knopp Kevin J. Insider CIK 1836523 · Aug 17, 2026 Director, President and CEO, issuer-wide	1,097,191	2.65%	-27,622	Aug 17, 2026	Director, President and CEO, issuer-wide
12	First Eagle Investment Management, LLC 13F CIK 1325447 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	929,985	2.25%	+126,379	Jun 30, 2026	carried, not yet filed for the newest quarter
12.1	First Eagle Small Cap Opportunity Fund Fund S000072438 · Registered fund · Jul 31, 2026 First Eagle Funds, not summed	860,882	2.08%	+137,219	Jul 31, 2026	First Eagle Funds, not summed
13	VANGUARD TOTAL STOCK MARKET INDEX FUND Fund S000002848 · Registered fund · Jun 30, 2026 VANGUARD INDEX FUNDS, not summed	919,827	2.23%	+137,170	Jun 30, 2026	VANGUARD INDEX FUNDS, not summed
14	Brown Christopher D. Insider CIK 1836988 · Oct 7, 2026 Director, issuer-wide	805,559	1.95%	+30,000	Oct 7, 2026	Director, issuer-wide
15	GEODE CAPITAL MANAGEMENT, LLC 13F CIK 1214717 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	761,797	1.84%	+66,342	Jun 30, 2026	carried, not yet filed for the newest quarter
16	Granahan Investment Management, LLC 13F CIK 1026710 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	692,092	1.67%	-2,978	Jun 30, 2026	carried, not yet filed for the newest quarter
17	STATE STREET CORP 13F CIK 93751 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	606,560	1.47%	-19,332	Jun 30, 2026	carried, not yet filed for the newest quarter
17.1	State Street(R) SPDR(R) S&P Kensho Future Security ETF Fund S000059702 · Registered fund · Jun 30, 2026 SPDR SERIES TRUST, not summed	85,312	0.21%	-30,222	Jun 30, 2026	SPDR SERIES TRUST, not summed
17.2	STATE STREET SMALL/MID CAP EQUITY INDEX PORTFOLIO Fund S000050332 · Registered fund · Jun 30, 2026 STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed	9,400	0.02%	0	Jun 30, 2026	STATE STREET INSTITUTIONAL INVESTMENT TRUST, not summed
17.3	State Street Total Return V.I.S. Fund Fund S000001637 · Registered fund · Jun 30, 2026 STATE STREET VARIABLE INSURANCE SERIES FUNDS INC, not summed	821	0.00%	-11	Jun 30, 2026	STATE STREET VARIABLE INSURANCE SERIES FUNDS INC, not summed
18	HRUSOVSKY E KEVIN Insider CIK 1252546 · Jun 10, 2026 Director, Executive Chairman, issuer-wide	495,065	1.20%	+14,083	Jun 10, 2026	Director, Executive Chairman, issuer-wide
19	ESSEX INVESTMENT MANAGEMENT CO LLC 13F CIK 201772 · Registered investment adviser · Sep 30, 2026	455,706	1.10%	-14,538	Sep 30, 2026
20	MORGAN STANLEY 13F CIK 895421 · Holding company · Jun 30, 2026 carried, not yet filed for the newest quarter	404,078	0.98%	+30,820	Jun 30, 2026	carried, not yet filed for the newest quarter
21	Prescott Group Capital Management, L.L.C. 13F CIK 1166152 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	361,595	0.87%	0	Jun 30, 2026	carried, not yet filed for the newest quarter
22	Meros Investment Management, LP 13F CIK 1911372 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	361,368	0.87%	-370	Jun 30, 2026	carried, not yet filed for the newest quarter
23	AMERICAN CENTURY COMPANIES INC 13F CIK 748054 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	359,848	0.87%	+303,954	Jun 30, 2026	carried, not yet filed for the newest quarter
24	VANGUARD EXTENDED MARKET INDEX FUND Fund S000002841 · Registered fund · Jun 30, 2026 VANGUARD INDEX FUNDS, not summed	340,050	0.82%	+29,118	Jun 30, 2026	VANGUARD INDEX FUNDS, not summed
25	HighMark Wealth Management LLC 13F CIK 1802451 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	339,783	0.82%	+20,433	Jun 30, 2026	carried, not yet filed for the newest quarter
26	NORTHERN TRUST CORP 13F CIK 73124 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	266,417	0.64%	+25,085	Jun 30, 2026	carried, not yet filed for the newest quarter
26.1	Small Cap Index Fund Fund S000001245 · Registered fund · Jun 30, 2026 Northern Funds, not summed	15,131	0.04%	+253	Jun 30, 2026	Northern Funds, not summed
26.2	Small Cap Core Fund Fund S000001244 · Registered fund · Jun 30, 2026 Northern Funds, not summed	10,903	0.03%	-444	Jun 30, 2026	Northern Funds, not summed
27	BANK OF AMERICA CORP /DE/ 13F CIK 70858 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	251,027	0.61%	+225,949	Jun 30, 2026	carried, not yet filed for the newest quarter
28	CHARLES SCHWAB INVESTMENT MANAGEMENT INC 13F CIK 884546 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	233,892	0.57%	+4,403	Jun 30, 2026	carried, not yet filed for the newest quarter
28.1	Schwab U.S. Small-Cap ETF Fund S000026636 · Registered fund · May 31, 2026 SCHWAB STRATEGIC TRUST, not summed	131,062	0.32%	-6,284	May 31, 2026	SCHWAB STRATEGIC TRUST, not summed
28.2	Schwab Small-Cap Index Fund Fund S000005912 · Registered fund · Jul 31, 2026 SCHWAB CAPITAL TRUST, not summed	71,808	0.17%	+11,532	Jul 31, 2026	SCHWAB CAPITAL TRUST, not summed
28.3	Schwab Total Stock Market Index Fund Fund S000005913 · Registered fund · Jul 31, 2026 SCHWAB CAPITAL TRUST, not summed	20,374	0.05%	0	Jul 31, 2026	SCHWAB CAPITAL TRUST, not summed
28.4	Schwab U.S. Broad Market ETF Fund S000026631 · Registered fund · May 31, 2026 SCHWAB STRATEGIC TRUST, not summed	15,500	0.04%	0	May 31, 2026	SCHWAB STRATEGIC TRUST, not summed
29	Amova Asset Management Americas, Inc. 13F CIK 1480751 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	228,681	0.55%	-41,192	Jun 30, 2026	carried, not yet filed for the newest quarter
30	Sumitomo Mitsui Trust Group, Inc. 13F CIK 1475365 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	228,681	0.55%	-41,192	Jun 30, 2026	carried, not yet filed for the newest quarter
31	VANGUARD PORTFOLIO MANAGEMENT LLC 13F CIK 2100121 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	194,858	0.47%	+31,164	Jun 30, 2026	carried, not yet filed for the newest quarter
32	RENAISSANCE TECHNOLOGIES LLC 13F CIK 1037389 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	191,900	0.46%	-38,300	Jun 30, 2026	carried, not yet filed for the newest quarter
33	VANGUARD FIDUCIARY TRUST CO 13F CIK 933478 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	186,056	0.45%	+5,806	Jun 30, 2026	carried, not yet filed for the newest quarter
34	RAYMOND JAMES FINANCIAL INC 13F CIK 720005 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	167,348	0.40%	-9,172	Jun 30, 2026	carried, not yet filed for the newest quarter
35	Legato Capital Management LLC 13F CIK 1442641 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	158,119	0.38%	+4,669	Jun 30, 2026	carried, not yet filed for the newest quarter
36	Russell Investments Group, Ltd. 13F CIK 1692234 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	149,655	0.36%	+4,326	Jun 30, 2026	carried, not yet filed for the newest quarter
36.1	U.S. Small Cap Equity Fund Fund S000006864 · Registered fund · Jun 30, 2026 RUSSELL INVESTMENT FUNDS, not summed	13,088	0.03%	0	Jun 30, 2026	RUSSELL INVESTMENT FUNDS, not summed
37	Victory Small Cap Stock Fund Fund S000012914 · Registered fund · Jul 31, 2026 Victory Portfolios III, not summed	149,337	0.36%	+922	Jul 31, 2026	Victory Portfolios III, not summed
38	VANGUARD RUSSELL 2000 INDEX FUND Fund S000030003 · Registered fund · May 31, 2026 VANGUARD SCOTTSDALE FUNDS, not summed	142,606	0.35%	+7,386	May 31, 2026	VANGUARD SCOTTSDALE FUNDS, not summed
39	Nuveen, LLC 13F CIK 1871926 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	141,727	0.34%	+40,653	Jun 30, 2026	carried, not yet filed for the newest quarter
39.1	Nuveen Equity Index Fund Fund S000005360 · Registered fund · Jul 31, 2026 TIAA-CREF Funds, not summed	64,194	0.16%	0	Jul 31, 2026	TIAA-CREF Funds, not summed
39.2	Nuveen Small Cap Blend Index Fund Fund S000005367 · Registered fund · Jul 31, 2026 TIAA-CREF Funds, not summed	38,433	0.09%	+8,228	Jul 31, 2026	TIAA-CREF Funds, not summed
39.3	TIAA Separate Account VA-1 - Stock Index Account Fund S000005098 · Registered fund · Jun 30, 2026 TIAA Separate Account VA-1, not summed	521	0.00%	0	Jun 30, 2026	TIAA Separate Account VA-1, not summed
39.4	Nuveen Life Stock Index Fund Fund S000005094 · Registered fund · Jun 30, 2026 TIAA-CREF Life Funds, not summed	380	0.00%	0	Jun 30, 2026	TIAA-CREF Life Funds, not summed
40	DIMENSIONAL FUND ADVISORS LP 13F CIK 354204 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	124,498	0.30%	+5,747	Jun 30, 2026	carried, not yet filed for the newest quarter
40.1	U.S. SMALL CAP PORTFOLIO Fund S000000971 · Registered fund · Jul 31, 2026 DFA INVESTMENT DIMENSIONS GROUP INC, not summed	30,370	0.07%	0	Jul 31, 2026	DFA INVESTMENT DIMENSIONS GROUP INC, not summed
40.2	Dimensional U.S. Small Cap ETF Fund S000070906 · Registered fund · Jul 31, 2026 Dimensional ETF Trust, not summed	15,399	0.04%	-6,873	Jul 31, 2026	Dimensional ETF Trust, not summed
40.3	Dimensional U.S. Core Equity 2 ETF Fund S000070903 · Registered fund · Jul 31, 2026 Dimensional ETF Trust, not summed	7,722	0.02%	—	Jul 31, 2026	Dimensional ETF Trust, not summed
40.4	U.S. MICRO CAP PORTFOLIO Fund S000000948 · Registered fund · Jul 31, 2026 DFA INVESTMENT DIMENSIONS GROUP INC, not summed	6,110	0.01%	0	Jul 31, 2026	DFA INVESTMENT DIMENSIONS GROUP INC, not summed
40.5	Dimensional US Sustainability Core 1 ETF Fund S000076639 · Registered fund · Jul 31, 2026 Dimensional ETF Trust, not summed	4,574	0.01%	—	Jul 31, 2026	Dimensional ETF Trust, not summed
41	Griffith Joseph H. IV Insider CIK 1431531 · Oct 6, 2026 Chief Financial Officer, issuer-wide	116,497	0.28%	-5,000	Oct 6, 2026	Chief Financial Officer, issuer-wide
42	1290 Essex Small Cap Growth Fund Fund S000076802 · Registered fund · Jul 31, 2026 1290 Funds, not summed	113,551	0.27%	0	Jul 31, 2026	1290 Funds, not summed
43	Campbell & CO Investment Adviser LLC 13F CIK 1353570 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	111,190	0.27%	+81,534	Jun 30, 2026	carried, not yet filed for the newest quarter
44	Mitsubishi UFJ Asset Management Co., Ltd. 13F CIK 1466546 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	110,557	0.27%	-21,909	Jun 30, 2026	carried, not yet filed for the newest quarter
45	NANO CAP NEW MILLENNIUM GROWTH FUND L P 13F CIK 1277890 · Unknown · Jun 30, 2026 carried, not yet filed for the newest quarter	107,500	0.26%	-12,500	Jun 30, 2026	carried, not yet filed for the newest quarter
46	AQR CAPITAL MANAGEMENT LLC 13F CIK 1167557 · Registered investment adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	103,909	0.25%	-497	Jun 30, 2026	carried, not yet filed for the newest quarter
46.1	AQR Small Cap Momentum Style Fund Fund S000025644 · Registered fund · Mar 31, 2026 AQR Funds, not summed	15,216	0.04%	—	Mar 31, 2026	AQR Funds, not summed
46.2	AQR Small Cap Multi-Style Fund Fund S000040064 · Registered fund · Jun 30, 2026 AQR Funds, not summed	14,522	0.04%	—	Jun 30, 2026	AQR Funds, not summed
47	ACUITAS US MICROCAP FUND Fund S000045890 · Registered fund · Jun 30, 2026 FORUM FUNDS II, not summed	100,953	0.24%	-28,913	Jun 30, 2026	FORUM FUNDS II, not summed
48	IQ EQ FUND MANAGEMENT (IRELAND) Ltd 13F CIK 1620943 · Exempt reporting adviser · Jun 30, 2026 carried, not yet filed for the newest quarter	98,689	0.24%	+8,920	Jun 30, 2026	carried, not yet filed for the newest quarter
49	Spoto Mark Insider CIK 1836585 · Jun 10, 2026 Director, issuer-wide	92,945	0.22%	—	Jun 10, 2026	Director, issuer-wide
50	BANK OF MONTREAL /CAN/ 13F CIK 927971 · Bank · Jun 30, 2026 carried, not yet filed for the newest quarter	87,346	0.21%	-29	Jun 30, 2026	carried, not yet filed for the newest quarter

9 more nested rows are not shown here; Every filing lists them all.

Shares are restated onto today's split basis. Change compares each row with the same holder's previous filing in the same source; a dash means there is none to compare. Nested 13D/G, insider and fund rows are not summed, since a 13F report already holds them.

Showing 1–50 of 190 holders

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Key facts CIK 1555279 CUSIP 65443P102 13F (30d) 12 filings 12 filers Visit website Investor relations