There is a long list of 161 institutional holders of OABI 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 OABI by largest to smallest position reported in the institutional investor's latest 13F filing. In the institutional-holders-of-OABI table below, the initial column indicates the name of each top institutional holder of OABI, with a link to that fund's top holdings. The next columns indicate the amount of OABI stock held by each of the institutional holders of OABI, followed by the OABI 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
Avista Capital Holdings L.P.	15,817,934	$95,383	12/31/2023
OABI	15,817,934	$95,383	12/31/2023
Janus Henderson Group PLC	7,777,897	$47,990	12/31/2023
OABI	7,777,897	$47,990	12/31/2023
BlackRock Inc.	7,287,819	$44,966	12/31/2023
OABI	7,287,819	$44,966	12/31/2023
Vanguard Group Inc.	5,651,408	$34,869	12/31/2023
OABI	5,651,408	$34,869	12/31/2023
Macquarie Group Ltd.	3,568,230	$22,018	12/31/2023
OABI	3,568,230	$22,018	12/31/2023
William Blair Investment Management LLC	3,337,241	$20,591	12/31/2023
OABI	3,337,241	$20,591	12/31/2023
Rubric Capital Management LP	2,850,588	$17,588	12/31/2023
OABI	2,850,588	$17,588	12/31/2023
Chicago Capital LLC	3,187,352	$17,275	03/31/2024
OABI	3,187,352	$17,275	03/31/2024
Private Management Group Inc.	2,639,651	$16,287	12/31/2023
OABI	2,639,651	$16,287	12/31/2023
Dimensional Fund Advisors LP	2,623,995	$16,190	12/31/2023
OABI	2,623,995	$16,190	12/31/2023
Rice Hall James & Associates LLC	2,640,541	$14,312	03/31/2024
OABI	2,640,541	$14,312	03/31/2024
Millennium Management LLC	2,276,418	$13,332	12/31/2023
OABI	2,276,418	$13,332	12/31/2023
Geode Capital Management LLC	2,151,555	$13,276	12/31/2023
OABI	2,151,555	$13,276	12/31/2023
State Street Corp	2,009,408	$12,398	12/31/2023
OABI	2,009,408	$12,398	12/31/2023
Villere ST Denis J & Co. LLC	2,078,294	$11,264	03/31/2024
OABI	2,078,294	$11,264	03/31/2024
First Sabrepoint Capital Management LP	1,657,173	$10,225	12/31/2023
OABI	1,657,173	$10,225	12/31/2023
Orchard Capital Managment LLC	1,358,028	$8,379	12/31/2023
OABI	1,358,028	$8,379	12/31/2023
Kornitzer Capital Management Inc. KS	1,219,955	$7,527	12/31/2023
OABI	1,219,955	$7,527	12/31/2023
Knott David M Jr	1,086,505	$6,704	12/31/2023
OABI	1,086,505	$6,704	12/31/2023
Northern Trust Corp	873,432	$5,389	12/31/2023
OABI	873,432	$5,389	12/31/2023
Impax Asset Management Group plc	848,184	$5,233	12/31/2023
OABI	848,184	$5,233	12/31/2023
Charles Schwab Investment Management Inc.	751,496	$4,637	12/31/2023
OABI	751,496	$4,637	12/31/2023
Woodstock Corp	748,428	$4,056	03/31/2024
OABI	748,428	$4,056	03/31/2024
Deutsche Bank AG	579,891	$3,578	12/31/2023
OABI	579,891	$3,578	12/31/2023
ADAR1 Capital Management LLC	478,171	$2,950	12/31/2023
OABI	478,171	$2,950	12/31/2023
Fuller & Thaler Asset Management Inc.	463,425	$2,859	12/31/2023
OABI	463,425	$2,859	12/31/2023
Morgan Stanley	458,362	$2,828	12/31/2023
OABI	458,362	$2,828	12/31/2023
Bank of America Corp DE	425,093	$2,623	12/31/2023
OABI	425,093	$2,623	12/31/2023
AWH Capital L.P.	422,401	$2,606	12/31/2023
OABI	422,401	$2,606	12/31/2023
Bank of New York Mellon Corp	423,169	$2,294	03/31/2024
OABI	423,169	$2,294	03/31/2024
Isthmus Partners LLC	310,774	$1,917	12/31/2023
OABI	310,774	$1,917	12/31/2023
Kent Lake Capital LLC	300,000	$1,851	12/31/2023
OABI	300,000	$1,851	12/31/2023
TLS Advisors LLC	250,185	$1,544	12/31/2023
OABI	250,185	$1,544	12/31/2023
D. E. Shaw & Co. Inc.	248,112	$1,531	12/31/2023
OABI	248,112	$1,531	12/31/2023
Connor Clark & Lunn Investment Management Ltd.	244,619	$1,509	12/31/2023
OABI	244,619	$1,509	12/31/2023
Nuveen Asset Management LLC	227,860	$1,406	12/31/2023
OABI	227,860	$1,406	12/31/2023
JPMorgan Chase & Co.	222,294	$1,372	12/31/2023
OABI	222,294	$1,372	12/31/2023
Goldman Sachs Group Inc.	189,437	$1,169	12/31/2023
OABI	189,437	$1,169	12/31/2023
Towerview LLC	175,000	$1,080	12/31/2023
OABI	175,000	$1,080	12/31/2023
Swiss National Bank	171,703	$1,059	12/31/2023
OABI	171,703	$1,059	12/31/2023
Cornerstone Capital Inc.	166,016	$1,024	12/31/2023
OABI	166,016	$1,024	12/31/2023
Royce & Associates LP	160,148	$988	12/31/2023
OABI	160,148	$988	12/31/2023
Rhumbline Advisers	158,520	$978	12/31/2023
OABI	158,520	$978	12/31/2023
Barclays PLC	145,298	$896	12/31/2023
OABI	145,298	$896	12/31/2023
UBS Group AG	122,664	$757	12/31/2023
OABI	122,664	$757	12/31/2023
FMR LLC	114,929	$709	12/31/2023
OABI	114,929	$709	12/31/2023
Alliancebernstein L.P.	113,685	$701	12/31/2023
OABI	113,685	$701	12/31/2023
Standard Life Aberdeen plc	103,708	$640	12/31/2023
OABI	103,708	$640	12/31/2023
California State Teachers Retirement System	93,118	$575	12/31/2023
OABI	93,118	$575	12/31/2023
Susquehanna International Group LLP		$550	12/31/2023
Call	81,600	$503	12/31/2023
OABI	44,703	$276	12/31/2023
Put	37,100	$229	12/31/2023