Who owns ATEX (ATEX)
Which tracked institutional funds hold ATEX, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See ATEX 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 ATEX is one-sided between 2025-Q4 and 2026-Q1: 61 added or opened and 13 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
ATEX’s largest tracked holder by dollar value, Owl Creek Asset Management, L.P., sizes it at 39.9% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 39.9pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in ATEX 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 132 tracked filers holding ATEX, 84 increased or opened the position and 49 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 ATEX 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 17
- VANGUARD CAPITAL MANAGEMENT LLC$22M
- PLUSTICK MANAGEMENT LLC$19M
- Potrero Capital Research LLC$9M
- VANGUARD PORTFOLIO MANAGEMENT LLC$6M
- Panoramic Capital, LLC$5M
- CenterBook Partners LP$5M
Full exits 10
- VANGUARD GROUP INC$20M
- Jefferies Financial Group Inc.$10M
- MARSHALL WACE, LLP$6M
- TUDOR INVESTMENT CORP ET AL$3M
- Qube Research & Technologies Ltd$3M
- Man Group plc$2M
Largest adds
- Owl Creek Asset Management, L.P.$89M
- Heard Capital LLC$28M
- BlackRock, Inc.$16M
- JANE STREET GROUP, LLC$13M
- DIMENSIONAL FUND ADVISORS LP$9M
- QVT Financial LP$8M
Largest trims
- D. E. Shaw & Co., Inc.$1M
- BARCLAYS PLC$328K
- Nuveen, LLC$287K
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 |
|---|---|---|---|---|
| Owl Creek Asset Management, L.P. | 5,411,776 | $207M | 27.4% | 2026-Q1 |
| Heard Capital LLC | 1,716,738 | $66M | 8.7% | 2026-Q1 |
| BlackRock, Inc. trimmed | 1,007,143 | $38M | 5.1% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 573,847 | $22M | 2.9% | 2026-Q1 |
| QVT Financial LP | 503,941 | $19M | 2.6% | 2026-Q1 |
| PLUSTICK MANAGEMENT LLC new | 499,596 | $19M | 2.5% | 2026-Q1 |
| GAMCO INVESTORS, INC. ET AL added | 425,820 | $16M | 2.2% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 424,856 | $16M | 2.2% | 2026-Q1 |
| JANE STREET GROUP, LLC added | 420,857 | $16M | 2.1% | 2026-Q1 |
| STATE STREET CORP added | 387,918 | $15M | 2.0% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 374,301 | $14M | 1.9% | 2026-Q1 |
| GARNET EQUITY CAPITAL HOLDINGS, INC. trimmed | 343,496 | $13M | 1.7% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC trimmed | 307,922 | $12M | 1.6% | 2026-Q1 |
| GABELLI FUNDS LLC trimmed | 265,800 | $10M | 1.3% | 2026-Q1 |
| Potrero Capital Research LLC new | 229,561 | $9M | 1.2% | 2026-Q1 |
| AYAL Capital Advisors Ltd trimmed | 197,119 | $8M | 1.0% | 2026-Q1 |
| HRT FINANCIAL LP added | 174,925 | $7M | 0.9% | 2026-Q1 |
| Potomac Capital Management, Inc. added | 173,802 | $7M | 0.9% | 2026-Q1 |
| DG Capital Management, LLC added | 168,217 | $6M | 0.9% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 167,781 | $6M | 0.8% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 164,542 | $6M | 0.8% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 161,786 | $6M | 0.8% | 2026-Q1 |
| CITADEL ADVISORS LLC added | 161,163 | $6M | 0.8% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 141,388 | $5M | 0.7% | 2026-Q1 |
| FMR LLC added | 135,295 | $5M | 0.7% | 2026-Q1 |
| Panoramic Capital, LLC new | 135,000 | $5M | 0.7% | 2026-Q1 |
| CenterBook Partners LP added | 127,674 | $5M | 0.6% | 2026-Q1 |
| CITIGROUP INC added | 119,861 | $5M | 0.6% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 119,456 | $5M | 0.6% | 2026-Q1 |
| NORTHERN TRUST CORP added | 117,610 | $4M | 0.6% | 2026-Q1 |
| KIRR MARBACH & CO LLC /IN/ added | 113,814 | $4M | 0.6% | 2026-Q1 |
| ARDSLEY ADVISORY PARTNERS LP new | 110,000 | $4M | 0.6% | 2026-Q1 |
| MORGAN STANLEY trimmed | 102,658 | $4M | 0.5% | 2026-Q1 |
| Beartown Capital Management, LLC trimmed | 100,000 | $4M | 0.5% | 2026-Q1 |
| GRATIA CAPITAL, LLC new | 87,500 | $3M | 0.4% | 2026-Q1 |
| Atom Investors LP added | 84,179 | $3M | 0.4% | 2026-Q1 |
| OpenArc Corporate Advisory, LLC new | 73,848 | $3M | 0.4% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 67,836 | $3M | 0.3% | 2026-Q1 |
| Waterfront Wealth Inc. added | 59,955 | $2M | 0.3% | 2026-Q1 |
| Squarepoint Ops LLC added | 59,736 | $2M | 0.3% | 2026-Q1 |
| Marble Bar Asset Management LLP added | 53,509 | $2M | 0.3% | 2026-Q1 |
| Teton Advisors, LLC | 53,000 | $2M | 0.3% | 2026-Q1 |
| Resolute Capital Asset Partners LLC added | 51,106 | $2M | 0.3% | 2026-Q1 |
| UBS Group AG trimmed | 47,875 | $2M | 0.2% | 2026-Q1 |
| 683 Capital Management, LLC new | 46,000 | $2M | 0.2% | 2026-Q1 |
| SIMPLEX TRADING, LLC added | 43,750 | $2M | 0.2% | 2026-Q1 |
| Campbell & CO Investment Adviser LLC added | 40,460 | $2M | 0.2% | 2026-Q1 |
| Trexquant Investment LP trimmed | 40,175 | $2M | 0.2% | 2026-Q1 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 39,798 | $2M | 0.2% | 2026-Q1 |
| Creative Planning added | 31,964 | $1M | 0.2% | 2026-Q1 |
| IMC-Chicago, LLC added | 30,363 | $1M | 0.2% | 2026-Q1 |
| Schonfeld Strategic Advisors LLC trimmed | 23,211 | $886K | 0.1% | 2026-Q1 |
| Nuveen, LLC trimmed | 22,875 | $874K | 0.1% | 2026-Q1 |
| Proficio Capital Partners LLC | 20,000 | $764K | 0.1% | 2026-Q1 |
| Apis Capital Advisors, LLC new | 19,740 | $754K | 0.1% | 2026-Q1 |
| WOODMONT INVESTMENT COUNSEL LLC added | 18,307 | $699K | 0.1% | 2026-Q1 |
| Virtu Financial LLC added | 17,885 | $683K | 0.1% | 2026-Q1 |
| GWN SECURITIES INC. new | 16,468 | $629K | 0.1% | 2026-Q1 |
| STRS OHIO trimmed | 15,700 | $600K | 0.1% | 2026-Q1 |
| Quantinno Capital Management LP added | 15,619 | $596K | 0.1% | 2026-Q1 |
| Quadrature Capital Ltd new | 14,502 | $554K | 0.1% | 2026-Q1 |
| RHUMBLINE ADVISERS trimmed | 14,115 | $539K | 0.1% | 2026-Q1 |
| Inspire Investing, LLC trimmed | 13,309 | $508K | 0.1% | 2026-Q1 |
| STATE OF WISCONSIN INVESTMENT BOARD trimmed | 13,269 | $507K | 0.1% | 2026-Q1 |
| Jefferson Bridge Capital, LLC | 12,950 | $495K | 0.1% | 2026-Q1 |
| FNY Investment Advisers, LLC added | 11,221 | $428K | 0.1% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC trimmed | 10,648 | $407K | 0.1% | 2026-Q1 |
| DEUTSCHE BANK AG\ added | 9,444 | $361K | 0.0% | 2026-Q1 |
| SBI Securities Co., Ltd. added | 74,983 | $38M | 5.0% | 2025-Q3 stale |
| VANGUARD GROUP INC trimmed | 931,305 | $20M | 2.7% | 2025-Q4 stale |
| Jefferies Financial Group Inc. added | 454,508 | $10M | 1.3% | 2025-Q4 stale |
| MARSHALL WACE, LLP added | 291,255 | $6M | 0.8% | 2025-Q4 stale |
| Roubaix Capital, LLC added | 161,706 | $6M | 0.8% | 2025-Q1 stale |
| Clearbridge Investments, LLC trimmed | 203,541 | $5M | 0.7% | 2025-Q2 stale |
| SCOGGIN MANAGEMENT LP trimmed | 225,000 | $5M | 0.6% | 2025-Q3 stale |
| TUDOR INVESTMENT CORP ET AL trimmed | 124,943 | $3M | 0.4% | 2025-Q4 stale |
| Qube Research & Technologies Ltd trimmed | 124,646 | $3M | 0.4% | 2025-Q4 stale |
| Man Group plc added | 100,145 | $2M | 0.3% | 2025-Q4 stale |
| GSA CAPITAL PARTNERS LLP added | 72,976 | $2M | 0.2% | 2025-Q4 stale |
| Harber Asset Management LLC new | 35,608 | $1M | 0.2% | 2025-Q1 stale |
| Teton Advisors, Inc. | 50,000 | $1M | 0.2% | 2025-Q2 stale |
| KETTLE HILL CAPITAL MANAGEMENT, LLC trimmed | 29,469 | $1M | 0.1% | 2025-Q1 stale |
| SG Americas Securities, LLC added | 48,509 | $1M | 0.1% | 2025-Q4 stale |
| Cubist Systematic Strategies, LLC trimmed | 25,658 | $939K | 0.1% | 2025-Q1 stale |
| BROWN ADVISORY INC new | 20,000 | $732K | 0.1% | 2025-Q1 stale |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP added | 33,401 | $729K | 0.1% | 2025-Q4 stale |
| HARVEST MANAGEMENT LLC new | 19,000 | $695K | 0.1% | 2025-Q1 stale |
| Y-Intercept (Hong Kong) Ltd trimmed | 31,400 | $674K | 0.1% | 2025-Q3 stale |
| GABELLI & Co INVESTMENT ADVISERS, INC. trimmed | 30,650 | $669K | 0.1% | 2025-Q4 stale |
| Magnetar Financial LLC new | 25,860 | $663K | 0.1% | 2025-Q2 stale |
| Engineers Gate Manager LP added | 27,051 | $581K | 0.1% | 2025-Q3 stale |
| Walleye Capital LLC added | 15,812 | $579K | 0.1% | 2025-Q1 stale |
| Swiss National Bank | 19,850 | $509K | 0.1% | 2025-Q2 stale |
| Allspring Global Investments Holdings, LLC added | 12,029 | $440K | 0.1% | 2025-Q1 stale |
| Sandia Investment Management LP trimmed | 20,000 | $437K | 0.1% | 2025-Q4 stale |
| Pekin Hardy Strauss, Inc. new | 16,250 | $417K | 0.1% | 2025-Q2 stale |
| Balyasny Asset Management L.P. trimmed | 17,740 | $387K | 0.1% | 2025-Q4 stale |
| Ancora Advisors LLC new | 10,144 | $371K | 0.0% | 2025-Q1 stale |
| Versor Investments LP added | 13,900 | $357K | 0.0% | 2025-Q2 stale |
| LPL Financial LLC trimmed | 13,640 | $350K | 0.0% | 2025-Q2 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.