Who owns ATEC (ATEC)
Which tracked institutional funds hold ATEC, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See ATEC 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 ATEC is one-sided between 2025-Q4 and 2026-Q1: 29 added or opened and 154 trimmed or exited — on balance reducing.
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
ATEC’s largest tracked holder by dollar value, VANGUARD GROUP 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 ATEC more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in ATEC 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 284 tracked filers holding ATEC, 166 increased or opened the position and 131 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 ATEC 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 11
- VANGUARD CAPITAL MANAGEMENT LLC$53M
- BRAIDWELL LP$24M
- VANGUARD PORTFOLIO MANAGEMENT LLC$12M
- VANGUARD FIDUCIARY TRUST CO$9M
- HARBOR CAPITAL ADVISORS, INC.$2M
- KORNITZER CAPITAL MANAGEMENT INC /KS$1M
Full exits 27
- VANGUARD GROUP INC$125M
- Driehaus Capital Management LLC$60M
- TWO SIGMA ADVISERS, LP$34M
- Iron Triangle Partners LP$27M
- M&G PLC$14M
- NORGES BANK$14M
Largest adds
- RAYMOND JAMES FINANCIAL INC$10M
- Qube Research & Technologies Ltd$6M
- Schonfeld Strategic Advisors LLC$6M
- Point72 Asset Management, L.P.$4M
- Parkman Healthcare Partners LLC$3M
- AQR CAPITAL MANAGEMENT LLC$2M
Largest trims
- BlackRock, Inc.$104M
- MORGAN STANLEY$73M
- AMERICAN CENTURY COMPANIES INC$67M
- DEUTSCHE BANK AG\$56M
- ROYAL BANK OF CANADA$54M
- Walleye Capital LLC$31M
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 | 10,088,182 | $110M | 7.2% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC trimmed | 6,424,777 | $70M | 4.6% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 4,913,779 | $53M | 3.5% | 2026-Q1 |
| ROYAL BANK OF CANADA trimmed | 4,516,592 | $49M | 3.2% | 2026-Q1 |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. added | 3,616,330 | $39M | 2.6% | 2026-Q1 |
| STATE STREET CORP added | 3,031,164 | $33M | 2.2% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 2,906,422 | $32M | 2.1% | 2026-Q1 |
| Nuveen, LLC trimmed | 2,849,413 | $31M | 2.0% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC added | 2,809,545 | $31M | 2.0% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 2,560,971 | $28M | 1.8% | 2026-Q1 |
| Point72 Asset Management, L.P. added | 2,493,575 | $27M | 1.8% | 2026-Q1 |
| NEXT CENTURY GROWTH INVESTORS LLC trimmed | 2,370,377 | $26M | 1.7% | 2026-Q1 |
| Hood River Capital Management LLC added | 2,300,899 | $25M | 1.6% | 2026-Q1 |
| TREMBLANT CAPITAL GROUP added | 2,192,084 | $24M | 1.6% | 2026-Q1 |
| BRAIDWELL LP added | 2,172,725 | $24M | 1.6% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 2,042,843 | $22M | 1.5% | 2026-Q1 |
| UBS Group AG added | 1,944,685 | $21M | 1.4% | 2026-Q1 |
| OBERWEIS ASSET MANAGEMENT INC/ added | 1,908,293 | $21M | 1.4% | 2026-Q1 |
| Cerity Partners LLC trimmed | 1,821,111 | $20M | 1.3% | 2026-Q1 |
| EMERALD ADVISERS, LLC added | 1,807,307 | $20M | 1.3% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC trimmed | 1,744,217 | $19M | 1.2% | 2026-Q1 |
| MORGAN STANLEY trimmed | 1,651,562 | $18M | 1.2% | 2026-Q1 |
| Penn Capital Management Company, LLC added | 1,396,942 | $15M | 1.0% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC added | 1,371,942 | $15M | 1.0% | 2026-Q1 |
| NORTHERN TRUST CORP trimmed | 1,358,741 | $15M | 1.0% | 2026-Q1 |
| MetLife Investment Management, LLC added | 1,327,843 | $14M | 1.0% | 2026-Q1 |
| DEUTSCHE BANK AG\ trimmed | 1,302,465 | $14M | 0.9% | 2026-Q1 |
| Aberdeen Group plc added | 1,292,606 | $14M | 0.9% | 2026-Q1 |
| NOMURA ASSET MANAGEMENT INTERNATIONAL INC. added | 1,292,107 | $14M | 0.9% | 2026-Q1 |
| Granite Investment Partners, LLC added | 1,195,156 | $13M | 0.9% | 2026-Q1 |
| NEW YORK STATE COMMON RETIREMENT FUND added | 1,183,930 | $13M | 0.8% | 2026-Q1 |
| EMERALD MUTUAL FUND ADVISERS TRUST added | 1,156,826 | $13M | 0.8% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 1,104,753 | $12M | 0.8% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC added | 1,055,100 | $11M | 0.8% | 2026-Q1 |
| RAYMOND JAMES FINANCIAL INC added | 1,005,303 | $11M | 0.7% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 978,068 | $11M | 0.7% | 2026-Q1 |
| KING LUTHER CAPITAL MANAGEMENT CORP added | 944,756 | $10M | 0.7% | 2026-Q1 |
| JANE STREET GROUP, LLC added | 878,549 | $10M | 0.6% | 2026-Q1 |
| CITADEL ADVISORS LLC trimmed | 857,339 | $9M | 0.6% | 2026-Q1 |
| Motley Fool Asset Management LLC added | 855,514 | $9M | 0.6% | 2026-Q1 |
| Parkman Healthcare Partners LLC added | 823,763 | $9M | 0.6% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 795,985 | $9M | 0.6% | 2026-Q1 |
| Qube Research & Technologies Ltd added | 795,578 | $9M | 0.6% | 2026-Q1 |
| Schonfeld Strategic Advisors LLC added | 766,383 | $8M | 0.5% | 2026-Q1 |
| First Eagle Investment Management, LLC added | 696,637 | $8M | 0.5% | 2026-Q1 |
| INTRINSIC EDGE CAPITAL MANAGEMENT LLC added | 649,428 | $7M | 0.5% | 2026-Q1 |
| Squarepoint Ops LLC added | 607,118 | $7M | 0.4% | 2026-Q1 |
| SEI INVESTMENTS CO added | 598,003 | $7M | 0.4% | 2026-Q1 |
| Motley Fool Wealth Management, LLC trimmed | 575,828 | $6M | 0.4% | 2026-Q1 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP added | 507,017 | $6M | 0.4% | 2026-Q1 |
| Trexquant Investment LP added | 457,237 | $5M | 0.3% | 2026-Q1 |
| FIRST TRUST ADVISORS LP trimmed | 447,114 | $5M | 0.3% | 2026-Q1 |
| CONGRESS ASSET MANAGEMENT CO added | 435,715 | $5M | 0.3% | 2026-Q1 |
| PDT Partners, LLC | 400,892 | $4M | 0.3% | 2026-Q1 |
| JPMORGAN CHASE & CO trimmed | 381,460 | $4M | 0.3% | 2026-Q1 |
| Connor, Clark & Lunn Investment Management Ltd. trimmed | 381,020 | $4M | 0.3% | 2026-Q1 |
| Rockefeller Capital Management L.P. trimmed | 350,828 | $4M | 0.3% | 2026-Q1 |
| Rock Springs Capital Management LP added | 350,000 | $4M | 0.3% | 2026-Q1 |
| Russell Investments Group, Ltd. added | 338,608 | $4M | 0.2% | 2026-Q1 |
| Kopp Family Office, LLC | 328,680 | $4M | 0.2% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 328,595 | $4M | 0.2% | 2026-Q1 |
| BANK OF MONTREAL /CAN/ trimmed | 326,297 | $4M | 0.2% | 2026-Q1 |
| PNC FINANCIAL SERVICES GROUP, INC. added | 318,319 | $3M | 0.2% | 2026-Q1 |
| GREAT LAKES ADVISORS, LLC added | 309,139 | $3M | 0.2% | 2026-Q1 |
| MERCER GLOBAL ADVISORS INC /ADV added | 305,118 | $3M | 0.2% | 2026-Q1 |
| LPL Financial LLC trimmed | 297,269 | $3M | 0.2% | 2026-Q1 |
| PRINCIPAL FINANCIAL GROUP INC added | 293,001 | $3M | 0.2% | 2026-Q1 |
| FMR LLC trimmed | 287,446 | $3M | 0.2% | 2026-Q1 |
| Engineers Gate Manager LP added | 286,467 | $3M | 0.2% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 272,397 | $3M | 0.2% | 2026-Q1 |
| TUDOR INVESTMENT CORP ET AL trimmed | 266,549 | $3M | 0.2% | 2026-Q1 |
| MARATHON CAPITAL MANAGEMENT added | 261,595 | $3M | 0.2% | 2026-Q1 |
| Assenagon Asset Management S.A. trimmed | 256,881 | $3M | 0.2% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. | 125,130 | $3M | 0.2% | 2026-Q1 |
| ROYCE & ASSOCIATES LP trimmed | 241,053 | $3M | 0.2% | 2026-Q1 |
| XTX Topco Ltd added | 233,742 | $3M | 0.2% | 2026-Q1 |
| Swiss National Bank | 233,500 | $3M | 0.2% | 2026-Q1 |
| Pier Capital, LLC trimmed | 223,159 | $2M | 0.2% | 2026-Q1 |
| HARBOR CAPITAL ADVISORS, INC. new | 217,701 | $2M | 0.2% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 5,945,140 | $125M | 8.2% | 2025-Q4 stale |
| Driehaus Capital Management LLC added | 2,858,771 | $60M | 4.0% | 2025-Q4 stale |
| TWO SIGMA ADVISERS, LP added | 1,635,100 | $34M | 2.3% | 2025-Q4 stale |
| Iron Triangle Partners LP new | 1,285,685 | $27M | 1.8% | 2025-Q4 stale |
| M&G PLC new | 669,266 | $14M | 0.9% | 2025-Q4 stale |
| NORGES BANK added | 649,814 | $14M | 0.9% | 2025-Q4 stale |
| Defilade Capital Management, L.P. new | 626,754 | $13M | 0.9% | 2025-Q4 stale |
| Freestone Grove Partners LP new | 615,420 | $13M | 0.9% | 2025-Q4 stale |
| Jefferies Financial Group Inc. added | 595,937 | $13M | 0.8% | 2025-Q4 stale |
| MACQUARIE GROUP LTD added | 809,350 | $12M | 0.8% | 2025-Q3 stale |
| Cubist Systematic Strategies, LLC trimmed | 679,050 | $10M | 0.6% | 2025-Q3 stale |
| BALYASNY ASSET MANAGEMENT L.P. added | 719,469 | $8M | 0.5% | 2025-Q2 stale |
| Lisanti Capital Growth, LLC added | 372,407 | $8M | 0.5% | 2025-Q4 stale |
| CASTLEARK MANAGEMENT LLC added | 296,160 | $6M | 0.4% | 2025-Q4 stale |
| OCCUDO QUANTITATIVE STRATEGIES LP added | 269,798 | $6M | 0.4% | 2025-Q4 stale |
| Informed Momentum Co LLC trimmed | 212,278 | $4M | 0.3% | 2025-Q4 stale |
| Blackstone Inc. new | 161,900 | $3M | 0.2% | 2025-Q4 stale |
| NOMURA HOLDINGS INC trimmed | 201,440 | $3M | 0.2% | 2025-Q3 stale |
| DeepCurrents Investment Group LLC new | 269,226 | $3M | 0.2% | 2025-Q1 stale |
| Quantbot Technologies LP added | 184,041 | $3M | 0.2% | 2025-Q3 stale |
| ExodusPoint Capital Management, LP trimmed | 171,714 | $2M | 0.2% | 2025-Q3 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.