On this page, we present all of the funds holding MASS from our database of 13F filers, detailed in the table below. The first column indicates the name of each of the funds holding MASS, with a link to that fund's top holdings. The next columns indicate the amount of MASS stock held by each of the funds holding MASS, followed by the MASS position size held by the fund, and lastly the date of the quarterly filing period the data represents. In total, we count 79 funds holding MASS within the last two filing periods in our coverage universe of 13F filers, with the largest position size having been reported by ARK Investment Management LLC. For more details on the positions held by ARK Investment Management LLC (or by any of the other funds holding MASS), click the fund name in the "Holder" column of the funds-holding-MASS table below.

Holder	Amount	Position Size ($ in 1000's)	As of
ARK Investment Management LLC	4,048,938	$30,569	03/31/2024
MASS	4,048,938	$30,569	03/31/2024
Granahan Investment Management Inc. MA	2,038,658	$22,874	12/31/2023
MASS	2,038,658	$22,874	12/31/2023
Ameriprise Financial Inc.	1,889,626	$21,202	12/31/2023
MASS	1,889,626	$21,202	12/31/2023
BlackRock Inc.	1,786,753	$20,047	12/31/2023
MASS	1,786,753	$20,047	12/31/2023
Vanguard Group Inc.	1,744,330	$19,571	12/31/2023
MASS	1,744,330	$19,571	12/31/2023
Eventide Asset Management LLC	1,430,995	$16,056	12/31/2023
MASS	1,430,995	$16,056	12/31/2023
Iron Triangle Partners LP	1,284,947	$14,417	12/31/2023
MASS	1,284,947	$14,417	12/31/2023
Fred Alger Management LLC	1,210,419	$13,581	12/31/2023
MASS	1,210,419	$13,581	12/31/2023
Platinum Investment Management Ltd.	781,871	$8,773	12/31/2023
MASS	781,871	$8,773	12/31/2023
AWM Investment Company Inc.	653,468	$7,332	12/31/2023
MASS	653,468	$7,332	12/31/2023
Nikko Asset Management Americas Inc.	582,034	$6,536	12/31/2023
MASS	582,034	$6,536	12/31/2023
Tao Capital Management LP	568,981	$6,384	12/31/2023
MASS	568,981	$6,384	12/31/2023
Geode Capital Management LLC	518,589	$5,819	12/31/2023
MASS	518,589	$5,819	12/31/2023
State Street Corp	407,313	$4,570	12/31/2023
MASS	407,313	$4,570	12/31/2023
Sumitomo Mitsui Trust Holdings Inc.	562,294	$4,245	03/31/2024
MASS	562,294	$4,245	03/31/2024
Sands Capital Ventures LLC	237,258	$2,662	12/31/2023
MASS	237,258	$2,662	12/31/2023
Northern Trust Corp	180,928	$2,030	12/31/2023
MASS	180,928	$2,030	12/31/2023
Charles Schwab Investment Management Inc.	180,661	$2,027	12/31/2023
MASS	180,661	$2,027	12/31/2023
Dimensional Fund Advisors LP	110,955	$1,245	12/31/2023
MASS	110,955	$1,245	12/31/2023
Nuveen Asset Management LLC	101,636	$1,140	12/31/2023
MASS	101,636	$1,140	12/31/2023
Tang Capital Management LLC	100,000	$1,122	12/31/2023
MASS	100,000	$1,122	12/31/2023
Renaissance Technologies LLC	96,900	$1,087	12/31/2023
MASS	96,900	$1,087	12/31/2023
New York State Common Retirement Fund	74,033	$831	12/31/2023
MASS	74,033	$831	12/31/2023
Morgan Stanley	70,325	$789	12/31/2023
MASS	70,325	$789	12/31/2023
Bruce & Co. Inc.	68,286	$766	12/31/2023
MASS	68,286	$766	12/31/2023
Citadel Advisors LLC		$740	12/31/2023
MASS	53,863	$604	12/31/2023
Call	13,000	$146	12/31/2023
Put	900	$10	12/31/2023
Bridgeway Capital Management Inc.	65,500	$735	12/31/2023
MASS	65,500	$735	12/31/2023
LPL Financial LLC	52,456	$589	12/31/2023
MASS	52,456	$589	12/31/2023
Bank of America Corp DE	45,271	$508	12/31/2023
MASS	45,271	$508	12/31/2023
Bank of New York Mellon Corp	65,338	$493	03/31/2024
MASS	65,338	$493	03/31/2024
Rhumbline Advisers	37,029	$415	12/31/2023
MASS	37,029	$415	12/31/2023
Barclays PLC	30,113	$338	12/31/2023
MASS	30,113	$338	12/31/2023
Susquehanna International Group LLP	29,731	$334	12/31/2023
MASS	29,731	$334	12/31/2023
Envestnet Asset Management Inc.	28,932	$325	12/31/2023
MASS	28,932	$325	12/31/2023
Goldman Sachs Group Inc.	28,279	$317	12/31/2023
MASS	28,279	$317	12/31/2023
Arete Wealth Advisors LLC	27,958	$314	12/31/2023
MASS	27,958	$314	12/31/2023
Primecap Management Co. CA	26,870	$301	12/31/2023
MASS	26,870	$301	12/31/2023
Alliancebernstein L.P.	26,030	$292	12/31/2023
MASS	26,030	$292	12/31/2023
Tower Research Capital LLC TRC	25,027	$281	12/31/2023
MASS	25,027	$281	12/31/2023
Millennium Management LLC	24,478	$275	12/31/2023
MASS	24,478	$275	12/31/2023
HRT Financial LP	24,023	$269	12/31/2023
MASS	24,023	$269	12/31/2023
Thrivent Financial for Lutherans	23,470	$263	12/31/2023
MASS	23,470	$263	12/31/2023
UBS Group AG	22,744	$255	12/31/2023
MASS	22,744	$255	12/31/2023
Campbell & CO Investment Adviser LLC	22,224	$249	12/31/2023
MASS	22,224	$249	12/31/2023
Point72 Asset Management L.P.	20,200	$227	12/31/2023
MASS	20,200	$227	12/31/2023
American Century Companies Inc.	19,973	$224	12/31/2023
MASS	19,973	$224	12/31/2023
State of Wisconsin Investment Board	17,834	$200	12/31/2023
MASS	17,834	$200	12/31/2023
JPMorgan Chase & Co.	14,542	$163	12/31/2023
MASS	14,542	$163	12/31/2023
Petrus Trust Company LTA	14,009	$157	12/31/2023
MASS	14,009	$157	12/31/2023
Jane Street Group LLC	13,500	$151	12/31/2023
MASS	13,500	$151	12/31/2023
Cresset Asset Management LLC	12,593	$141	12/31/2023
MASS	12,593	$141	12/31/2023
Two Sigma Securities LLC	12,480	$140	12/31/2023
MASS	12,480	$140	12/31/2023
MetLife Investment Management LLC	11,990	$135	12/31/2023
MASS	11,990	$135	12/31/2023
SG Americas Securities LLC	11,861	$133	12/31/2023
MASS	11,861	$133	12/31/2023
Mirae Asset Global Investments Co. Ltd.	11,175	$125	12/31/2023
MASS	11,175	$125	12/31/2023
American International Group Inc.	10,902	$122	12/31/2023
MASS	10,902	$122	12/31/2023
US Bancorp DE	10,604	$119	12/31/2023
MASS	10,604	$119	12/31/2023
Deutsche Bank AG	10,369	$116	12/31/2023
MASS	10,369	$116	12/31/2023
Values First Advisors Inc.	12,575	$95	03/31/2024
MASS	12,575	$95	03/31/2024
Wells Fargo & Company MN	8,264	$93	12/31/2023
MASS	8,264	$93	12/31/2023
Advisor Group Holdings Inc.	7,034	$79	12/31/2023
MASS	7,034	$79	12/31/2023
Royal Bank of Canada	6,916	$77	12/31/2023
MASS	6,916	$77	12/31/2023
Group One Trading L.P.		$53	12/31/2023
Call	5,000	$56	12/31/2023
Put	300	$3	12/31/2023
California State Teachers Retirement System	3,610	$41	12/31/2023
MASS	3,610	$41	12/31/2023
Allworth Financial LP	5,269	$40	03/31/2024
MASS	5,269	$40	03/31/2024
Citigroup Inc.	3,158	$35	12/31/2023
MASS	3,158	$35	12/31/2023
Signaturefd LLC	2,500	$28	12/31/2023
MASS	2,500	$28	12/31/2023
Zurcher Kantonalbank Zurich Cantonalbank	3,640	$27	03/31/2024
MASS	3,640	$27	03/31/2024
Nisa Investment Advisors LLC	2,412	$27	12/31/2023
MASS	2,412	$27	12/31/2023
Legal & General Group Plc	1,821	$20	12/31/2023
MASS	1,821	$20	12/31/2023
Metropolitan Life Insurance Co NY	1,440	$16	12/31/2023
MASS	1,440	$16	12/31/2023
Ameritas Investment Partners Inc.	1,442	$16	12/31/2023
MASS	1,442	$16	12/31/2023
FMR LLC	1,338	$15	12/31/2023
MASS	1,338	$15	12/31/2023
Quest Partners LLC	1,240	$14	12/31/2023
MASS	1,240	$14	12/31/2023
Amalgamated Bank	766	$6	03/31/2024
MASS	766	$6	03/31/2024
GPS Wealth Strategies Group LLC	275	$3	12/31/2023
MASS	275	$3	12/31/2023
Comerica Bank	165	$2	12/31/2023
MASS	165	$2	12/31/2023
The PNC Financial Services Group Inc.	6	$0	12/31/2023
MASS	6	$0	12/31/2023
Proequities Inc.		$0	12/31/2023
Put	0	$0	12/31/2023
Call	0	$0	12/31/2023
MASS	0	$0	12/31/2023
PEAK6 Investments LLC	24,800	$-128	12/31/2023
Put	36,200	$406	12/31/2023
Call	24,800	$278	12/31/2023