Who owns Oil States International, Inc. (OIS)
Which tracked institutional funds hold OIS, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See OIS company fundamentals →
Ownership as of the 2026-Q1 13F filings (latest filed 2026-05-18). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
The tracked-fund tape on OIS is one-sided between 2025-Q4 and 2026-Q1: 88 added or opened and 11 trimmed or exited — on balance accumulating.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
OIS’s largest tracked holder by dollar value, BlackRock, Inc., sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp gap the other way — the median holder sizes OIS more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in OIS divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2025-Q4 and 2026-Q1, across 215 tracked filers holding OIS, 131 increased or opened the position and 82 reduced or closed it; over the same quarter, there were no open-market insider Form 4s.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in OIS between the 2025-Q4 and 2026-Q1 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 19
- VANGUARD CAPITAL MANAGEMENT LLC$28M
- VANGUARD PORTFOLIO MANAGEMENT LLC$19M
- Driehaus Capital Management LLC$15M
- MARSHALL WACE, LLP$11M
- VANGUARD FIDUCIARY TRUST CO$4M
- O'SHAUGHNESSY ASSET MANAGEMENT, LLC$2M
Full exits 4
- VANGUARD GROUP INC$27M
- Thomist Capital Management, LP$2M
- TWO SIGMA ADVISERS, LP$1M
- Walleye Capital LLC$604K
Largest adds
- BlackRock, Inc.$28M
- DIMENSIONAL FUND ADVISORS LP$18M
- ACADIAN ASSET MANAGEMENT LLC$11M
- AMERICAN CENTURY COMPANIES INC$11M
- STATE STREET CORP$10M
- MORGAN STANLEY$9M
Largest trims
- GENDELL JEFFREY L$7M
- M&T Bank Corp$2M
- PRUDENTIAL FINANCIAL INC$1M
- Nierenberg Investment Management Company, LLC$621K
- BARCLAYS PLC$544K
- HSBC HOLDINGS PLC$483K
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| BlackRock, Inc. trimmed | 6,309,631 | $73M | 11.4% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 3,522,143 | $41M | 6.4% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 2,417,559 | $28M | 4.4% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC trimmed | 2,352,385 | $27M | 4.2% | 2026-Q1 |
| D. E. Shaw & Co., Inc. trimmed | 2,167,272 | $25M | 3.9% | 2026-Q1 |
| First Eagle Investment Management, LLC trimmed | 2,043,709 | $24M | 3.7% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC added | 1,848,308 | $22M | 3.3% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC added | 1,812,908 | $21M | 3.3% | 2026-Q1 |
| STATE STREET CORP added | 1,733,499 | $20M | 3.1% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 1,636,824 | $19M | 3.0% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 1,357,790 | $16M | 2.5% | 2026-Q1 |
| MORGAN STANLEY added | 1,350,160 | $16M | 2.4% | 2026-Q1 |
| Driehaus Capital Management LLC new | 1,328,078 | $15M | 2.4% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 1,131,609 | $13M | 2.0% | 2026-Q1 |
| KENNEDY CAPITAL MANAGEMENT LLC trimmed | 1,078,399 | $13M | 1.9% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 1,073,304 | $12M | 1.9% | 2026-Q1 |
| HOTCHKIS & WILEY CAPITAL MANAGEMENT LLC trimmed | 1,001,051 | $12M | 1.8% | 2026-Q1 |
| MARSHALL WACE, LLP added | 932,772 | $11M | 1.7% | 2026-Q1 |
| UBS Group AG added | 853,474 | $10M | 1.5% | 2026-Q1 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC trimmed | 832,905 | $10M | 1.5% | 2026-Q1 |
| JPMORGAN CHASE & CO trimmed | 821,868 | $10M | 1.5% | 2026-Q1 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP added | 721,401 | $8M | 1.3% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC added | 704,411 | $8M | 1.3% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 702,085 | $8M | 1.3% | 2026-Q1 |
| Trexquant Investment LP added | 551,183 | $6M | 1.0% | 2026-Q1 |
| PANAGORA ASSET MANAGEMENT INC trimmed | 539,920 | $6M | 1.0% | 2026-Q1 |
| NORTHERN TRUST CORP added | 461,591 | $5M | 0.8% | 2026-Q1 |
| AMERIPRISE FINANCIAL INC trimmed | 456,119 | $5M | 0.8% | 2026-Q1 |
| JANE STREET GROUP, LLC added | 454,245 | $5M | 0.8% | 2026-Q1 |
| SEI INVESTMENTS CO added | 441,725 | $5M | 0.8% | 2026-Q1 |
| FEDERATED HERMES, INC. added | 414,123 | $5M | 0.7% | 2026-Q1 |
| Empowered Funds, LLC added | 402,205 | $5M | 0.7% | 2026-Q1 |
| FRANKLIN RESOURCES INC added | 395,901 | $5M | 0.7% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 365,048 | $4M | 0.7% | 2026-Q1 |
| Connor, Clark & Lunn Investment Management Ltd. added | 361,554 | $4M | 0.7% | 2026-Q1 |
| Hara Capital LLC trimmed | 336,828 | $4M | 0.6% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 324,428 | $4M | 0.6% | 2026-Q1 |
| Invesco Ltd. added | 311,490 | $4M | 0.6% | 2026-Q1 |
| Russell Investments Group, Ltd. added | 309,464 | $4M | 0.6% | 2026-Q1 |
| DEUTSCHE BANK AG\ trimmed | 301,566 | $4M | 0.5% | 2026-Q1 |
| MASSACHUSETTS FINANCIAL SERVICES CO /MA/ trimmed | 299,371 | $3M | 0.5% | 2026-Q1 |
| GENDELL JEFFREY L trimmed | 298,317 | $3M | 0.5% | 2026-Q1 |
| FMR LLC added | 266,603 | $3M | 0.5% | 2026-Q1 |
| HRT FINANCIAL LP added | 244,517 | $3M | 0.4% | 2026-Q1 |
| EverSource Wealth Advisors, LLC added | 59,647 | $3M | 0.4% | 2026-Q1 |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM trimmed | 222,793 | $3M | 0.4% | 2026-Q1 |
| LSV ASSET MANAGEMENT trimmed | 216,400 | $3M | 0.4% | 2026-Q1 |
| Qube Research & Technologies Ltd trimmed | 198,511 | $2M | 0.4% | 2026-Q1 |
| Fisher Asset Management, LLC trimmed | 198,305 | $2M | 0.4% | 2026-Q1 |
| RAYMOND JAMES FINANCIAL INC added | 193,930 | $2M | 0.4% | 2026-Q1 |
| STATE OF WISCONSIN INVESTMENT BOARD trimmed | 160,815 | $2M | 0.3% | 2026-Q1 |
| Creative Planning added | 157,809 | $2M | 0.3% | 2026-Q1 |
| O'SHAUGHNESSY ASSET MANAGEMENT, LLC added | 157,731 | $2M | 0.3% | 2026-Q1 |
| LOS ANGELES CAPITAL MANAGEMENT LLC added | 155,815 | $2M | 0.3% | 2026-Q1 |
| IEQ CAPITAL, LLC added | 154,598 | $2M | 0.3% | 2026-Q1 |
| Informed Momentum Co LLC new | 153,896 | $2M | 0.3% | 2026-Q1 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 129,982 | $2M | 0.2% | 2026-Q1 |
| Campbell & CO Investment Adviser LLC trimmed | 129,947 | $2M | 0.2% | 2026-Q1 |
| Vanguard Global Advisers, LLC new | 129,727 | $2M | 0.2% | 2026-Q1 |
| Nuveen, LLC trimmed | 126,152 | $1M | 0.2% | 2026-Q1 |
| PRUDENTIAL FINANCIAL INC trimmed | 115,896 | $1M | 0.2% | 2026-Q1 |
| Y-Intercept (Hong Kong) Ltd added | 104,723 | $1M | 0.2% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 99,890 | $1M | 0.2% | 2026-Q1 |
| Assenagon Asset Management S.A. | 99,684 | $1M | 0.2% | 2026-Q1 |
| RHUMBLINE ADVISERS trimmed | 95,417 | $1M | 0.2% | 2026-Q1 |
| Engineers Gate Manager LP added | 93,777 | $1M | 0.2% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ trimmed | 92,836 | $1M | 0.2% | 2026-Q1 |
| JACOBS LEVY EQUITY MANAGEMENT, INC added | 92,804 | $1M | 0.2% | 2026-Q1 |
| STIFEL FINANCIAL CORP trimmed | 90,982 | $1M | 0.2% | 2026-Q1 |
| WEDGE CAPITAL MANAGEMENT L L P/NC trimmed | 90,526 | $1M | 0.2% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS added | 87,951 | $1M | 0.2% | 2026-Q1 |
| WINTON GROUP Ltd added | 87,927 | $1M | 0.2% | 2026-Q1 |
| CWM, LLC added | 87,926 | $1M | 0.2% | 2026-Q1 |
| Mariner, LLC added | 86,237 | $1M | 0.2% | 2026-Q1 |
| CITIGROUP INC added | 85,186 | $992K | 0.2% | 2026-Q1 |
| PRINCIPAL FINANCIAL GROUP INC trimmed | 85,105 | $991K | 0.2% | 2026-Q1 |
| JB CAPITAL PARTNERS LP | 85,000 | $989K | 0.2% | 2026-Q1 |
| MARTINGALE ASSET MANAGEMENT L P new | 76,328 | $888K | 0.1% | 2026-Q1 |
| Counterpoint Mutual Funds LLC added | 73,084 | $851K | 0.1% | 2026-Q1 |
| Point72 Asset Management, L.P. added | 70,343 | $819K | 0.1% | 2026-Q1 |
| Integrated Quantitative Investments LLC new | 64,681 | $753K | 0.1% | 2026-Q1 |
| VICTORY CAPITAL MANAGEMENT INC trimmed | 64,113 | $746K | 0.1% | 2026-Q1 |
| BARCLAYS PLC trimmed | 62,995 | $733K | 0.1% | 2026-Q1 |
| ExodusPoint Capital Management, LP added | 62,017 | $722K | 0.1% | 2026-Q1 |
| Cambria Investment Management, L.P. added | 58,712 | $683K | 0.1% | 2026-Q1 |
| Gotham Asset Management, LLC added | 57,963 | $675K | 0.1% | 2026-Q1 |
| Hillsdale Investment Management Inc. added | 57,500 | $669K | 0.1% | 2026-Q1 |
| Magnetar Financial LLC new | 52,722 | $614K | 0.1% | 2026-Q1 |
| STRS OHIO trimmed | 51,900 | $604K | 0.1% | 2026-Q1 |
| State of Wyoming added | 51,607 | $601K | 0.1% | 2026-Q1 |
| ROYAL BANK OF CANADA trimmed | 49,536 | $576K | 0.1% | 2026-Q1 |
| Harvest Investment Services, LLC added | 48,320 | $562K | 0.1% | 2026-Q1 |
| WEALTH ENHANCEMENT ADVISORY SERVICES, LLC added | 49,998 | $560K | 0.1% | 2026-Q1 |
| Cerity Partners LLC added | 45,498 | $530K | 0.1% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 3,932,397 | $27M | 4.1% | 2025-Q4 stale |
| Thomist Capital Management, LP new | 288,084 | $2M | 0.3% | 2025-Q4 stale |
| TWO SIGMA ADVISERS, LP added | 203,355 | $1M | 0.2% | 2025-Q4 stale |
| SEGALL BRYANT & HAMILL, LLC new | 165,204 | $1M | 0.2% | 2025-Q3 stale |
| TUDOR INVESTMENT CORP ET AL added | 122,719 | $632K | 0.1% | 2025-Q1 stale |
| Walleye Capital LLC added | 89,197 | $604K | 0.1% | 2025-Q4 stale |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.