Who owns ATEN (ATEN)
Which tracked institutional funds hold ATEN, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See ATEN company fundamentals →
Ownership as of the 2026-Q1 13F filings. 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 ATEN is one-sided between 2025-Q4 and 2026-Q1: 116 added or opened and 30 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
ATEN’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 ATEN more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in ATEN 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 266 tracked filers holding ATEN, 157 increased or opened the position and 117 reduced or closed it; over the same quarter, open-market insider Form 4 buying and selling roughly offset.
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 ATEN 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 22
- VANGUARD PORTFOLIO MANAGEMENT LLC$78M
- VANGUARD CAPITAL MANAGEMENT LLC$72M
- JANE STREET GROUP, LLC$14M
- DEPRINCE RACE & ZOLLO INC$13M
- OBERWEIS ASSET MANAGEMENT INC/$12M
- VANGUARD FIDUCIARY TRUST CO$11M
Full exits 13
- VANGUARD GROUP INC$118M
- TWO SIGMA ADVISERS, LP$8M
- Alyeska Investment Group, L.P.$5M
- AlphaQuest LLC$3M
- WEDGE CAPITAL MANAGEMENT L L P/NC$2M
- October Effect Ltd$2M
Largest adds
- PRUDENTIAL FINANCIAL INC$19M
- TWO SIGMA INVESTMENTS, LP$18M
- STATE STREET CORP$16M
- ARROWSTREET CAPITAL, LIMITED PARTNERSHIP$15M
- ROYAL BANK OF CANADA$12M
- BARCLAYS PLC$11M
Largest trims
- BlackRock, Inc.$18M
- Invesco Ltd.$8M
- Qube Research & Technologies Ltd$7M
- FIRST TRUST ADVISORS LP$4M
- Trexquant Investment LP$2M
- PRICE T ROWE ASSOCIATES INC /MD/$2M
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 | 9,136,923 | $211M | 12.7% | 2026-Q1 |
| Penserra Capital Management LLC trimmed | 3,594,112 | $83M | 5.0% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 3,387,848 | $78M | 4.7% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 3,121,015 | $72M | 4.3% | 2026-Q1 |
| STATE STREET CORP trimmed | 3,090,185 | $71M | 4.3% | 2026-Q1 |
| Boston Trust Walden Corp trimmed | 2,173,261 | $50M | 3.0% | 2026-Q1 |
| WELLINGTON MANAGEMENT GROUP LLP trimmed | 1,909,203 | $44M | 2.7% | 2026-Q1 |
| BARCLAYS PLC added | 1,874,502 | $43M | 2.6% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 1,784,987 | $41M | 2.5% | 2026-Q1 |
| FIRST TRUST ADVISORS LP trimmed | 1,719,817 | $40M | 2.4% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC trimmed | 1,717,406 | $40M | 2.4% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP trimmed | 1,635,947 | $38M | 2.3% | 2026-Q1 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 1,556,176 | $36M | 2.2% | 2026-Q1 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP added | 1,497,144 | $35M | 2.1% | 2026-Q1 |
| PUNCH & ASSOCIATES INVESTMENT MANAGEMENT, INC. added | 1,459,910 | $34M | 2.0% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 1,319,989 | $31M | 1.8% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 1,186,743 | $27M | 1.7% | 2026-Q1 |
| PRICE T ROWE ASSOCIATES INC /MD/ trimmed | 1,072,838 | $25M | 1.5% | 2026-Q1 |
| PRUDENTIAL FINANCIAL INC added | 885,207 | $20M | 1.2% | 2026-Q1 |
| Boston Partners trimmed | 815,790 | $19M | 1.1% | 2026-Q1 |
| ROYCE & ASSOCIATES LP added | 817,430 | $19M | 1.1% | 2026-Q1 |
| MORGAN STANLEY added | 813,087 | $19M | 1.1% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 743,968 | $17M | 1.0% | 2026-Q1 |
| NORTHERN TRUST CORP added | 704,404 | $16M | 1.0% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 660,639 | $15M | 0.9% | 2026-Q1 |
| JANE STREET GROUP, LLC added | 595,948 | $14M | 0.8% | 2026-Q1 |
| DEPRINCE RACE & ZOLLO INC trimmed | 564,800 | $13M | 0.8% | 2026-Q1 |
| ROYAL BANK OF CANADA added | 536,461 | $12M | 0.7% | 2026-Q1 |
| CITADEL ADVISORS LLC added | 514,020 | $12M | 0.7% | 2026-Q1 |
| OBERWEIS ASSET MANAGEMENT INC/ added | 504,300 | $12M | 0.7% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 494,433 | $11M | 0.7% | 2026-Q1 |
| Impax Asset Management Group plc added | 470,000 | $11M | 0.7% | 2026-Q1 |
| Aptus Capital Advisors, LLC added | 455,002 | $11M | 0.6% | 2026-Q1 |
| PRINCIPAL FINANCIAL GROUP INC trimmed | 436,279 | $10M | 0.6% | 2026-Q1 |
| Defiance ETFs, LLC trimmed | 423,138 | $10M | 0.6% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC added | 414,920 | $10M | 0.6% | 2026-Q1 |
| PARADIGM CAPITAL MANAGEMENT INC/NY | 401,400 | $9M | 0.6% | 2026-Q1 |
| Bridge City Capital, LLC added | 400,683 | $9M | 0.6% | 2026-Q1 |
| UBS Group AG trimmed | 390,055 | $9M | 0.5% | 2026-Q1 |
| Russell Investments Group, Ltd. added | 389,780 | $9M | 0.5% | 2026-Q1 |
| BNP PARIBAS FINANCIAL MARKETS added | 389,712 | $9M | 0.5% | 2026-Q1 |
| RICE HALL JAMES & ASSOCIATES, LLC added | 336,824 | $8M | 0.5% | 2026-Q1 |
| WELLS FARGO & COMPANY/MN added | 332,534 | $8M | 0.5% | 2026-Q1 |
| CRAWFORD INVESTMENT COUNSEL INC added | 320,622 | $7M | 0.4% | 2026-Q1 |
| HRT FINANCIAL LP added | 320,380 | $7M | 0.4% | 2026-Q1 |
| JPMORGAN CHASE & CO added | 326,646 | $7M | 0.4% | 2026-Q1 |
| Man Group plc added | 304,441 | $7M | 0.4% | 2026-Q1 |
| Invesco Ltd. trimmed | 294,980 | $7M | 0.4% | 2026-Q1 |
| NORGES BANK added | 416,672 | $7M | 0.4% | 2026-Q1 |
| Jump Financial, LLC added | 287,458 | $7M | 0.4% | 2026-Q1 |
| D. E. Shaw & Co., Inc. added | 263,387 | $6M | 0.4% | 2026-Q1 |
| Public Sector Pension Investment Board added | 255,787 | $6M | 0.4% | 2026-Q1 |
| TUDOR INVESTMENT CORP ET AL trimmed | 238,857 | $6M | 0.3% | 2026-Q1 |
| NEW YORK STATE COMMON RETIREMENT FUND added | 235,727 | $5M | 0.3% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC trimmed | 222,369 | $5M | 0.3% | 2026-Q1 |
| PEREGRINE CAPITAL MANAGEMENT LLC trimmed | 219,619 | $5M | 0.3% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 206,670 | $5M | 0.3% | 2026-Q1 |
| SUMMIT PARTNERS L P added | 200,065 | $5M | 0.3% | 2026-Q1 |
| RHUMBLINE ADVISERS added | 192,110 | $4M | 0.3% | 2026-Q1 |
| Legal & General Group Plc trimmed | 190,616 | $4M | 0.3% | 2026-Q1 |
| HARBOR CAPITAL ADVISORS, INC. trimmed | 187,130 | $4M | 0.3% | 2026-Q1 |
| IQ EQ FUND MANAGEMENT (IRELAND) Ltd trimmed | 175,194 | $4M | 0.2% | 2026-Q1 |
| HSBC HOLDINGS PLC added | 175,780 | $4M | 0.2% | 2026-Q1 |
| BESSEMER GROUP INC | 171,223 | $4M | 0.2% | 2026-Q1 |
| VOYA INVESTMENT MANAGEMENT LLC trimmed | 166,478 | $4M | 0.2% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 161,554 | $4M | 0.2% | 2026-Q1 |
| Nuveen, LLC trimmed | 158,571 | $4M | 0.2% | 2026-Q1 |
| Qube Research & Technologies Ltd trimmed | 157,546 | $4M | 0.2% | 2026-Q1 |
| Swiss National Bank | 142,400 | $3M | 0.2% | 2026-Q1 |
| Banque Cantonale Vaudoise trimmed | 139,472 | $3M | 0.2% | 2026-Q1 |
| VICTORY CAPITAL MANAGEMENT INC trimmed | 137,352 | $3M | 0.2% | 2026-Q1 |
| Connor, Clark & Lunn Investment Management Ltd. trimmed | 136,346 | $3M | 0.2% | 2026-Q1 |
| STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM trimmed | 129,607 | $3M | 0.2% | 2026-Q1 |
| Hillsdale Investment Management Inc. trimmed | 127,661 | $3M | 0.2% | 2026-Q1 |
| Creative Planning added | 127,268 | $3M | 0.2% | 2026-Q1 |
| Quantbot Technologies LP added | 124,535 | $3M | 0.2% | 2026-Q1 |
| AMERIPRISE FINANCIAL INC trimmed | 123,539 | $3M | 0.2% | 2026-Q1 |
| SEI INVESTMENTS CO trimmed | 121,241 | $3M | 0.2% | 2026-Q1 |
| TRUIST FINANCIAL CORP added | 115,015 | $3M | 0.2% | 2026-Q1 |
| Hennion & Walsh Asset Management, Inc. added | 114,096 | $3M | 0.2% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 108,222 | $3M | 0.2% | 2026-Q1 |
| Uniplan Investment Counsel, Inc. new | 106,268 | $2M | 0.1% | 2026-Q1 |
| FEDERATED HERMES, INC. trimmed | 106,267 | $2M | 0.1% | 2026-Q1 |
| FRANKLIN RESOURCES INC added | 103,999 | $2M | 0.1% | 2026-Q1 |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND added | 98,907 | $2M | 0.1% | 2026-Q1 |
| AEGON ASSET MANAGEMENT UK Plc new | 98,800 | $2M | 0.1% | 2026-Q1 |
| PDT Partners, LLC added | 98,626 | $2M | 0.1% | 2026-Q1 |
| MARTINGALE ASSET MANAGEMENT L P trimmed | 96,223 | $2M | 0.1% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 6,666,403 | $118M | 7.1% | 2025-Q4 stale |
| TWO SIGMA ADVISERS, LP added | 474,000 | $8M | 0.5% | 2025-Q4 stale |
| ALGERT GLOBAL LLC trimmed | 323,575 | $6M | 0.4% | 2025-Q2 stale |
| Alyeska Investment Group, L.P. trimmed | 272,093 | $5M | 0.3% | 2025-Q4 stale |
| HUSSMAN STRATEGIC ADVISORS, INC. new | 210,000 | $4M | 0.2% | 2025-Q3 stale |
| Assenagon Asset Management S.A. added | 200,510 | $4M | 0.2% | 2025-Q3 stale |
| Informed Momentum Co LLC added | 202,826 | $3M | 0.2% | 2025-Q1 stale |
| MARSHALL WACE, LLP trimmed | 175,083 | $3M | 0.2% | 2025-Q3 stale |
| AlphaQuest LLC added | 162,685 | $3M | 0.2% | 2025-Q4 stale |
| Vident Advisory, LLC added | 130,361 | $3M | 0.2% | 2025-Q2 stale |
| LPL Financial LLC added | 119,215 | $2M | 0.1% | 2025-Q2 stale |
| WEDGE CAPITAL MANAGEMENT L L P/NC added | 120,897 | $2M | 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.