Who owns Atkore (ATKR)
Which tracked institutional funds hold ATKR, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See ATKR company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 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 ATKR is one-sided between 2026-Q1 and 2026-Q2: 128 added or opened and 42 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
ATKR’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 ATKR more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in ATKR 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 2026-Q1 and 2026-Q2, across 310 tracked filers holding ATKR, 177 increased or opened the position and 142 reduced or closed it; over the same quarter, open-market insider Form 4s were net sales.
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 ATKR between the 2026-Q1 and 2026-Q2 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 26
- Boston Partners$28M
- Trexquant Investment LP$9M
- Aventail Capital Group, LP$7M
- TOWLE & CO$7M
- Edgestream Partners, L.P.$4M
- Point72 Asset Management, L.P.$4M
Full exits 25
- LSV ASSET MANAGEMENT$62M
- Coliseum Capital Management, LLC$56M
- NORGES BANK$10M
- VOLORIDGE INVESTMENT MANAGEMENT, LLC$5M
- CITADEL ADVISORS LLC$4M
- Allianz SE$4M
Largest adds
- BlackRock, Inc.$82M
- AMERICAN CENTURY COMPANIES INC$50M
- VANGUARD PORTFOLIO MANAGEMENT LLC$38M
- Irenic Capital Management LP$38M
- VANGUARD CAPITAL MANAGEMENT LLC$27M
- DIMENSIONAL FUND ADVISORS LP$26M
Largest trims
- FIRST TRUST ADVISORS LP$32M
- Gates Capital Management, Inc.$28M
- CANYON CAPITAL ADVISORS LLC$7M
- CANADA PENSION PLAN INVESTMENT BOARD$7M
- DEUTSCHE BANK AG\$6M
- ARROWSTREET CAPITAL, LIMITED PARTNERSHIP$4M
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| BlackRock, Inc. added | 3,116,222 | $237M | 10.5% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC added | 2,122,380 | $161M | 7.1% | 2026-Q2 |
| AMERICAN CENTURY COMPANIES INC added | 1,775,158 | $135M | 6.0% | 2026-Q2 |
| Gates Capital Management, Inc. trimmed | 1,710,192 | $130M | 5.8% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC added | 1,524,252 | $116M | 5.1% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 1,299,786 | $99M | 4.4% | 2026-Q2 |
| STATE STREET CORP added | 906,421 | $69M | 3.0% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 902,486 | $69M | 3.0% | 2026-Q2 |
| EARNEST PARTNERS LLC trimmed | 772,294 | $59M | 2.6% | 2026-Q2 |
| Hill City Capital, LP trimmed | 724,106 | $55M | 2.4% | 2026-Q2 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 575,607 | $44M | 1.9% | 2026-Q2 |
| Harding Loevner LP trimmed | 567,192 | $43M | 1.9% | 2026-Q2 |
| FIRST TRUST ADVISORS LP trimmed | 533,063 | $41M | 1.8% | 2026-Q2 |
| JPMORGAN CHASE & CO added | 520,864 | $39M | 1.7% | 2026-Q2 |
| JACOBS LEVY EQUITY MANAGEMENT, INC added | 519,275 | $39M | 1.7% | 2026-Q2 |
| Irenic Capital Management LP added | 507,613 | $39M | 1.7% | 2026-Q2 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 482,239 | $37M | 1.6% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 453,964 | $35M | 1.5% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ trimmed | 438,802 | $33M | 1.5% | 2026-Q2 |
| TWO SIGMA INVESTMENTS, LP added | 402,131 | $31M | 1.4% | 2026-Q2 |
| GENDELL JEFFREY L | 400,214 | $30M | 1.3% | 2026-Q2 |
| LONDON CO OF VIRGINIA added | 386,827 | $29M | 1.3% | 2026-Q2 |
| MORGAN STANLEY added | 378,566 | $29M | 1.3% | 2026-Q2 |
| Oslo Pensjonsforsikring AS | 377,000 | $29M | 1.3% | 2026-Q2 |
| VICTORY CAPITAL MANAGEMENT INC trimmed | 371,385 | $28M | 1.2% | 2026-Q2 |
| Boston Partners trimmed | 367,806 | $28M | 1.2% | 2026-Q2 |
| NEW YORK STATE COMMON RETIREMENT FUND trimmed | 341,215 | $26M | 1.1% | 2026-Q2 |
| NORTHERN TRUST CORP added | 335,441 | $26M | 1.1% | 2026-Q2 |
| Swedbank AB | 296,206 | $23M | 1.0% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC added | 288,586 | $22M | 1.0% | 2026-Q2 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC added | 252,429 | $19M | 0.8% | 2026-Q2 |
| Bank of New York Mellon Corp added | 247,645 | $19M | 0.8% | 2026-Q2 |
| SEI INVESTMENTS CO added | 244,346 | $19M | 0.8% | 2026-Q2 |
| Nuveen, LLC added | 238,992 | $18M | 0.8% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 223,986 | $17M | 0.8% | 2026-Q2 |
| Empowered Funds, LLC added | 204,012 | $16M | 0.7% | 2026-Q2 |
| BARCLAYS PLC added | 197,509 | $15M | 0.7% | 2026-Q2 |
| PDT Partners, LLC added | 191,253 | $15M | 0.6% | 2026-Q2 |
| FEDERATED HERMES, INC. added | 184,141 | $14M | 0.6% | 2026-Q2 |
| Allianz Asset Management GmbH added | 181,838 | $14M | 0.6% | 2026-Q2 |
| Qube Research & Technologies Ltd added | 178,249 | $14M | 0.6% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN trimmed | 155,867 | $12M | 0.5% | 2026-Q2 |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND added | 150,669 | $11M | 0.5% | 2026-Q2 |
| D. E. Shaw & Co., Inc. added | 145,448 | $11M | 0.5% | 2026-Q2 |
| CANYON CAPITAL ADVISORS LLC trimmed | 139,700 | $11M | 0.5% | 2026-Q2 |
| HOTCHKIS & WILEY CAPITAL MANAGEMENT LLC trimmed | 139,446 | $11M | 0.5% | 2026-Q2 |
| DNB Asset Management AS trimmed | 130,833 | $10M | 0.4% | 2026-Q2 |
| Russell Investments Group, Ltd. added | 125,124 | $10M | 0.4% | 2026-Q2 |
| Trexquant Investment LP added | 113,413 | $9M | 0.4% | 2026-Q2 |
| Allspring Global Investments Holdings, LLC added | 106,066 | $8M | 0.3% | 2026-Q2 |
| CANADA PENSION PLAN INVESTMENT BOARD trimmed | 102,900 | $8M | 0.3% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC trimmed | 100,279 | $8M | 0.3% | 2026-Q2 |
| Man Group plc trimmed | 98,582 | $7M | 0.3% | 2026-Q2 |
| Aventail Capital Group, LP added | 94,600 | $7M | 0.3% | 2026-Q2 |
| Woodline Partners LP trimmed | 94,232 | $7M | 0.3% | 2026-Q2 |
| Invesco Ltd. trimmed | 93,910 | $7M | 0.3% | 2026-Q2 |
| NORDEA INVESTMENT MANAGEMENT AB trimmed | 89,807 | $7M | 0.3% | 2026-Q2 |
| TOWLE & CO new | 85,793 | $7M | 0.3% | 2026-Q2 |
| BNP PARIBAS FINANCIAL MARKETS added | 83,548 | $6M | 0.3% | 2026-Q2 |
| Universal- Beteiligungs- und Servicegesellschaft mbH added | 74,805 | $6M | 0.3% | 2026-Q2 |
| KESTREL INVESTMENT MANAGEMENT CORP | 74,150 | $6M | 0.2% | 2026-Q2 |
| Rock Point Advisors, LLC trimmed | 71,688 | $5M | 0.2% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC added | 70,553 | $5M | 0.2% | 2026-Q2 |
| MARTINGALE ASSET MANAGEMENT L P added | 70,155 | $5M | 0.2% | 2026-Q2 |
| JANE STREET GROUP, LLC added | 68,185 | $5M | 0.2% | 2026-Q2 |
| Swiss National Bank added | 67,700 | $5M | 0.2% | 2026-Q2 |
| ENVESTNET ASSET MANAGEMENT INC trimmed | 66,747 | $5M | 0.2% | 2026-Q2 |
| PRUDENTIAL FINANCIAL INC added | 65,330 | $5M | 0.2% | 2026-Q2 |
| Caisse de depot et placement du Quebec added | 63,513 | $5M | 0.2% | 2026-Q2 |
| RAYMOND JAMES FINANCIAL INC trimmed | 57,742 | $4M | 0.2% | 2026-Q2 |
| Engineers Gate Manager LP added | 57,071 | $4M | 0.2% | 2026-Q2 |
| Edgestream Partners, L.P. added | 56,665 | $4M | 0.2% | 2026-Q2 |
| UBS Group AG trimmed | 53,561 | $4M | 0.2% | 2026-Q2 |
| Tidal Investments LLC added | 51,660 | $4M | 0.2% | 2026-Q2 |
| Defiance ETFs, LLC added | 51,660 | $4M | 0.2% | 2026-Q2 |
| XTX Topco Ltd added | 50,831 | $4M | 0.2% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC trimmed | 50,520 | $4M | 0.2% | 2026-Q2 |
| Point72 Asset Management, L.P. added | 49,751 | $4M | 0.2% | 2026-Q2 |
| RHUMBLINE ADVISERS added | 46,500 | $4M | 0.2% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 45,457 | $3M | 0.2% | 2026-Q2 |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. trimmed | 44,800 | $3M | 0.2% | 2026-Q2 |
| ALGERT GLOBAL LLC trimmed | 43,510 | $3M | 0.1% | 2026-Q2 |
| DENALI ADVISORS LLC trimmed | 42,900 | $3M | 0.1% | 2026-Q2 |
| Brevan Howard Capital Management LP added | 42,459 | $3M | 0.1% | 2026-Q2 |
| O'SHAUGHNESSY ASSET MANAGEMENT, LLC trimmed | 41,658 | $3M | 0.1% | 2026-Q2 |
| OPPENHEIMER ASSET MANAGEMENT INC. trimmed | 39,010 | $3M | 0.1% | 2026-Q2 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM trimmed | 38,455 | $3M | 0.1% | 2026-Q2 |
| ISTHMUS PARTNERS, LLC added | 38,120 | $3M | 0.1% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. added | 36,560 | $2M | 0.1% | 2026-Q2 |
| DEUTSCHE BANK AG\ trimmed | 36,324 | $3M | 0.1% | 2026-Q2 |
| Ausbil Investment Management Ltd added | 35,147 | $3M | 0.1% | 2026-Q2 |
| DEAN INVESTMENT ASSOCIATES, LLC added | 34,631 | $3M | 0.1% | 2026-Q2 |
| Legal & General Group Plc added | 33,144 | $3M | 0.1% | 2026-Q2 |
| VANGUARD ASSET MANAGEMENT, Ltd | 30,988 | $2M | 0.1% | 2026-Q2 |
| HSBC HOLDINGS PLC added | 29,846 | $2M | 0.1% | 2026-Q2 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 28,858 | $2M | 0.1% | 2026-Q2 |
| Linden Thomas Advisory Services, LLC added | 28,856 | $2M | 0.1% | 2026-Q2 |
| CenterBook Partners LP new | 28,144 | $2M | 0.1% | 2026-Q2 |
| BALYASNY ASSET MANAGEMENT L.P. trimmed | 28,014 | $2M | 0.1% | 2026-Q2 |
| Dean Capital Management added | 25,154 | $2M | 0.1% | 2026-Q2 |
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.