376 institutional investment managers reported OII positions in their Form 13F filings for Q2 2026, holding 104,297,756 shares worth $4.2B in total. BlackRock, Inc. reported the largest position.

Are funds buying or selling OII?

In Q2 2026, 63 managers opened new OII positions, 143 added, 108 trimmed and 53 sold out. Managers that filed in both quarters added a net 2,752,743 shares.

How current is this OII institutional ownership data?

It covers holdings as of the end of Q2 2026. Managers have 45 days after the quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.

Funds · OII

Who owns OII?

Institutional ownership of Oceaneering International Inc. from Form 13F, Q2 2026

376 institutional managers reported holding Oceaneering International Inc. (OII) in Form 13F filings for Q2 2026, with 104,297,756 shares worth $4.2B. The largest reported holder was BlackRock, Inc. Managers that filed both quarters added a net 2,752,743 shares (+2.7%). 63 opened new positions and 53 sold out.

Funds holding: 376
Value held: $4.2B
New / sold out: 63 / 53
Net shares, same filers: +2.7%

Holdings as of June 30, 2026, the end of Q2 2026. Managers have 45 days after a quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.

Largest holders of OII

Fund	Value	Share of 13F holdings	Shares	Move
BlackRock, Inc.	$665M	15.7%	16,403,230	Added
Vanguard Portfolio Management LLC	$321M	7.6%	7,926,938	Added
State Street Corp	$202M	4.8%	4,994,403	Trimmed
Brown Advisory Inc	$201M	4.8%	4,967,307	Trimmed
Vanguard Capital Management LLC	$182M	4.3%	4,485,268	Added
American Century Companies Inc	$163M	3.9%	4,023,994	Added
Earnest Partners LLC	$144M	3.4%	3,547,295	Trimmed
Dimensional Fund Advisors LP	$144M	3.4%	3,546,908	Added
Neuberger Berman Group LLC	$131M	3.1%	3,228,635	Added
Morgan Stanley Institutional Investment Advisors LLC	$124M	2.9%	3,066,015	Trimmed
Franklin Resources Inc	$124M	2.9%	3,060,961	Added
Geode Capital Management, LLC	$115M	2.7%	2,839,554	Added
Barrow Hanley Mewhinney & Strauss LLC	$92.1M	2.2%	2,272,949	Added
Greenhouse Funds LLLP	$76.8M	1.8%	1,896,343	Trimmed
Van Eck Associates Corp	$75.0M	1.8%	1,849,926	Trimmed
Reinhart Partners, LLC.	$66.8M	1.6%	1,648,423	New
Loomis Sayles & Co L P	$65.1M	1.5%	1,606,095	Trimmed
Northern Trust Corp	$55.6M	1.3%	1,371,471	Added
Charles Schwab Investment Management Inc	$54.3M	1.3%	1,339,591	Trimmed
Nomura Asset Management International Inc.	$53.9M	1.3%	1,330,080	New
Price T Rowe Associates Inc	$53.5M	1.3%	1,320,910	Added
Morgan Stanley	$48.9M	1.2%	1,207,487	Added
Bank of New York Mellon Corp	$45.7M	1.1%	1,126,793	Added
Goldman Sachs Group Inc	$43.6M	1.0%	1,076,557	Added
Royal Bank of Canada	$37.8M	0.9%	932,192	Trimmed

Share of 13F holdings is each fund's shares as a share of the 104,297,756 OII shares all 13F filers reported, not of shares outstanding.

Biggest buyers in Q2 2026

Franklin Resources Inc Added+$90.5M
Reinhart Partners, LLC. New+$66.8M
Nomura Asset Management International Inc. New+$53.9M
Barrow Hanley Mewhinney & Strauss LLC Added+$34.5M
Geode Capital Management, LLC Added+$18.8M
Bank of New York Mellon Corp Added+$15.1M
Vanguard Portfolio Management LLC Added+$14.1M
Bessemer Group Inc Added+$13.3M
Hennessy Advisors Inc New+$10.8M
American Century Companies Inc Added+$10.4M

Biggest sellers in Q2 2026

Brown Advisory Inc Trimmed-$33.3M
Boston Partners Sold out-$30.3M
Qube Research & Technologies Ltd Sold out-$20.9M
Fort Washington Investment Advisors Inc Sold out-$18.7M
Algert Global LLC Trimmed-$16.2M
Morgan Stanley Institutional Investment Advisors LLC Trimmed-$15.7M
Agf Management LTD Sold out-$13.0M
Barclays PLC Trimmed-$11.4M
Van Eck Associates Corp Trimmed-$8.6M
Schroder Investment Management Group Trimmed-$8.1M

The change in shares since the quarter before, adjusted for stock splits and priced at the Q2 2026 value per share. Funds bought $429M and sold $301M; 143 added and 108 trimmed.

Schedule 13D and 13G filings on OII

Owners of more than 5% must file within days, so these can be newer than the 13F data.

2026-11-10STATE STREET CORP SCHEDULE 13G filed by State Street CorporationSchedule 13G
2026-05-12STATE STREET CORP SCHEDULE 13G filed by State Street CorporationSchedule 13G
2025-02-06STATE STREET CORP SCHEDULE 13G filed by State Street CorporationSchedule 13G

Questions about OII ownership

Who owns OII stock?: 376 institutional investment managers reported OII positions in their Form 13F filings for Q2 2026, holding 104,297,756 shares worth $4.2B in total. BlackRock, Inc. reported the largest position.
Are funds buying or selling OII?: In Q2 2026, 63 managers opened new OII positions, 143 added, 108 trimmed and 53 sold out. Managers that filed in both quarters added a net 2,752,743 shares.
How current is this OII institutional ownership data?: It covers holdings as of the end of Q2 2026. Managers have 45 days after the quarter ends to file Form 13F (by August 14, 2026 for Q2 2026), so positions may have changed since.

From the SEC's Form 13F data sets for Q2 2026: every 13F holdings report, matched to OII by CUSIP. Options are left out. OII news and filings · OII insider trades · Top funds