There is a long list of 74 institutional holders of OPTN within the last two holding periods in our database of 13F filers, so we've sorted through to present to you just the top 50 institutional holders of OPTN by largest to smallest position reported in the institutional investor's latest 13F filing. In the institutional-holders-of-OPTN table below, the initial column indicates the name of each top institutional holder of OPTN, with a link to that fund's top holdings. The next columns indicate the amount of OPTN stock held by each of the institutional holders of OPTN, followed by the OPTN position size held by the institution, and finally the date of the quarterly 13F filing period the holdings data represents for that institution.

Holder	Amount	Position Size ($ in 1000's)	As of
FMR LLC	14,666,941	$18,920	12/31/2023
OPTN	14,666,941	$18,920	12/31/2023
MVM Partners LLC	14,605,263	$18,768	12/31/2023
OPTN	14,605,263	$18,768	12/31/2023
Great Point Partners LLC	8,839,939	$11,404	12/31/2023
OPTN	8,839,939	$11,404	12/31/2023
Rosalind Advisors Inc.	4,541,489	$6,631	03/31/2024
OPTN	4,541,489	$6,631	03/31/2024
BlackRock Inc.	4,404,251	$5,681	12/31/2023
OPTN	4,404,251	$5,681	12/31/2023
Vanguard Group Inc.	4,179,704	$5,392	12/31/2023
OPTN	4,179,704	$5,392	12/31/2023
Bleichroeder LP	4,045,132	$5,218	12/31/2023
OPTN	4,045,132	$5,218	12/31/2023
Kingdon Capital Management L.L.C.	3,899,237	$5,030	12/31/2023
OPTN	3,899,237	$5,030	12/31/2023
Velan Capital Investment Management LP	3,796,861	$4,898	12/31/2023
OPTN	3,796,861	$4,898	12/31/2023
Nantahala Capital Management LLC	3,146,921	$4,060	12/31/2023
OPTN	3,146,921	$4,060	12/31/2023
Massachusetts Financial Services Co. MA	2,853,929	$3,682	12/31/2023
OPTN	2,853,929	$3,682	12/31/2023
Levin Easterly Partners LLC	2,038,039	$2,976	03/31/2024
OPTN	2,038,039	$2,976	03/31/2024
Geode Capital Management LLC	1,459,354	$1,883	12/31/2023
OPTN	1,459,354	$1,883	12/31/2023
State Street Corp	1,295,413	$1,671	12/31/2023
OPTN	1,295,413	$1,671	12/31/2023
Rice Hall James & Associates LLC	993,268	$1,450	03/31/2024
OPTN	993,268	$1,450	03/31/2024
Northern Trust Corp	615,288	$794	12/31/2023
OPTN	615,288	$794	12/31/2023
Bank of New York Mellon Corp	356,637	$521	03/31/2024
OPTN	356,637	$521	03/31/2024
Bridgeway Capital Management Inc.	338,100	$436	12/31/2023
OPTN	338,100	$436	12/31/2023
Prelude Capital Management LLC	270,000	$348	12/31/2023
OPTN	270,000	$348	12/31/2023
GMT Capital Corp	240,917	$311	12/31/2023
OPTN	240,917	$311	12/31/2023
Morgan Stanley	237,303	$306	12/31/2023
OPTN	237,303	$306	12/31/2023
Charles Schwab Investment Management Inc.	202,809	$262	12/31/2023
OPTN	202,809	$262	12/31/2023
BNP Paribas Arbitrage SA	178,513	$261	03/31/2024
OPTN	178,513	$261	03/31/2024
Renaissance Technologies LLC	186,100	$240	12/31/2023
OPTN	186,100	$240	12/31/2023
Barclays PLC	149,777	$193	12/31/2023
OPTN	149,777	$193	12/31/2023
Palumbo Wealth Management LLC	119,028	$174	03/31/2024
OPTN	119,028	$174	03/31/2024
Millennium Management LLC	117,787	$152	12/31/2023
OPTN	117,787	$152	12/31/2023
Nuveen Asset Management LLC	112,190	$145	12/31/2023
OPTN	112,190	$145	12/31/2023
Brown Brothers Harriman & Co.	100,000	$129	12/31/2023
OPTN	100,000	$129	12/31/2023
Assenagon Asset Management S.A.	87,096	$127	03/31/2024
OPTN	87,096	$127	03/31/2024
Rhumbline Advisers	91,275	$118	12/31/2023
OPTN	91,275	$118	12/31/2023
Goldman Sachs Group Inc.	91,078	$117	12/31/2023
OPTN	91,078	$117	12/31/2023
GSA Capital Partners LLP	76,010	$111	03/31/2024
OPTN	76,010	$111	03/31/2024
UBS Group AG	78,118	$101	12/31/2023
OPTN	78,118	$101	12/31/2023
Jane Street Group LLC	61,156	$79	12/31/2023
OPTN	61,156	$79	12/31/2023
Bank of America Corp DE	56,014	$72	12/31/2023
OPTN	56,014	$72	12/31/2023
JPMorgan Chase & Co.	51,293	$66	12/31/2023
OPTN	51,293	$66	12/31/2023
New York State Common Retirement Fund	47,832	$62	12/31/2023
OPTN	47,832	$62	12/31/2023
American International Group Inc.	36,243	$47	12/31/2023
OPTN	36,243	$47	12/31/2023
Prudential Financial Inc.	36,440	$47	12/31/2023
OPTN	36,440	$47	12/31/2023
HighTower Advisors LLC	30,235	$44	03/31/2024
OPTN	30,235	$44	03/31/2024
Mariner LLC	34,171	$44	12/31/2023
OPTN	34,171	$44	12/31/2023
Invesco Ltd.	32,371	$42	12/31/2023
OPTN	32,371	$42	12/31/2023
HighMark Wealth Management LLC	25,000	$36	03/31/2024
OPTN	25,000	$36	03/31/2024
Citadel Advisors LLC	25,623	$33	12/31/2023
OPTN	25,623	$33	12/31/2023
Susquehanna International Group LLP	24,908	$32	12/31/2023
OPTN	24,908	$32	12/31/2023
Royal Bank of Canada	23,079	$30	12/31/2023
OPTN	23,079	$30	12/31/2023
Hsbc Holdings PLC	21,978	$29	12/31/2023
OPTN	21,978	$29	12/31/2023
Wells Fargo & Company MN	19,157	$25	12/31/2023
OPTN	19,157	$25	12/31/2023
State Board of Administration of Florida Retirement System	18,938	$24	12/31/2023
OPTN	18,938	$24	12/31/2023