Among active 13F managers last quarter, 4 opened and 2 added, while 2 reduced; the largest holder to move was EcoR1 Capital, LLC (16× the prior stake). Over the last 180 days, 2 insiders bought and 3 insiders sold, a net +$2.5M in open-market trades.
Funds lean in and no leg opposes.
32 tracked 13F filers disclose a position in ATRA as of the latest SEC 13F filings, a combined $41.4M in reported value. Holders and values reflect the 13F filers Arkolith currently tracks, not the entire institutional universe. Counts and totals are a floor, not the full institutional ownership.
| # | Fund | Shares | Position value | Last move | As of | History |
|---|---|---|---|---|---|---|
| 1 | EcoR1 Capital, LLC | 1.6M | $17.8M | ▲16× Added · +1.5M sh | Q2 2026 | |
| 2 | Adage Capital Partners GP, L.L.C. | 700K | $3.3M | ▲New +700K sh | Q1 2026 | |
| 3 | Point72 Asset Management, L.P. | 688K | $7.9M | ▲+254% Added · +493K sh | Q2 2026 | |
| 4 | Redmile Group, LLC | 442K | $5.1M | —Held | Q2 2026 | |
| 5 | Vanguard Capital Management LLC | 247K | $2.8M | ▲+13% Added · +29K sh | Q2 2026 | |
| 6 | BlackRock, Inc. | 84K | $970K | ▲+6.9% Added · +5K sh | Q2 2026 | |
| 7 | Geode Capital Management, LLC | 75K | $863K | ▲+14% Added · +9K sh | Q2 2026 | |
| 8 | UBS Group AG | 50K | $237K | ▲36× Added · +49K sh | Q1 2026 | |
| 9 | Staley Capital Advisers Inc | 50K | $574K | —Held | Q2 2026 | |
| 10 | Millennium Management LLC | 48K | $226K | ▲New +48K sh | Q1 2026 | |
| 11 | Vanguard Fiduciary Trust Co | 43K | $494K | ▲+28% Added · +9K sh | Q2 2026 | |
| 12 | Jane Street Group, LLC | 34K | $160K | ▲+142% Added · +20K sh | Q1 2026 | |
| 13 | State Street Corp | 26K | $304K | —Held | Q2 2026 | |
| 14 | FMR LLC | 16K | $186K | —Held | Q2 2026 | |
| 15 | Bridgeway Capital Management, LLC | 14K | $161K | ▼−57% Reduced · −19K sh | Q2 2026 | |
| 16 | Northern Trust Corp | 12K | $58K | —Held | Q1 2026 | |
| 17 | Citadel Advisors LLC | 10K | $117K | ▲New +10K sh | Q2 2026 | |
| 18 | Morgan Stanley | 9K | $43K | ▼−43% Reduced · −7K sh | Q1 2026 | |
| 19 | Royal Bank Of Canada | 4K | $20K | ▲+408% Added · +3K sh | Q1 2026 | |
| 20 | Vanguard Global Advisers, LLC | 1K | $17K | —Held | Q2 2026 | |
| 21 | SBI Securities Co., Ltd. | 1K | $16K | ▼−11% Reduced · −170 sh | Q2 2026 | |
| 22 | Jones Financial Companies LLLP | 703 | $3K | —Held | Q1 2026 | |
| 23 | Caitong International Asset Management Co., Ltd | 311 | $4K | ▲New +311 sh | Q2 2026 | |
| 24 | Wells Fargo & Company | 251 | $1K | —Held | Q1 2026 | |
| 25 | JPMorgan Chase & Co | 216 | $933 | —Held | Q1 2026 |
Holders and values reflect the 13F filers Arkolith currently tracks, not the entire institutional universe. Counts and totals are a floor, not the full institutional ownership.
Last quarter, 4 funds opened a new position in ATRA and 2 added to an existing one, while 2 reduced. Based on 13F filings from active, signal-eligible managers (passive index funds and other mechanical holders are excluded from this count).
| Company | Co-held by | Their position there |
|---|---|---|
| Nvidia CorpNVDA | 9 funds | $9.2B |
| Amazon.com IncAMZN | 9 funds | $6.7B |
| Advanced Micro DevicesAMD | 9 funds | $2.5B |
| Eli Lilly & CoLLY | 9 funds | $2.4B |
| JPMorgan Chase & CoJPM | 9 funds | $2.1B |
| Mastercard Inc - AMA | 9 funds | $1.8B |
| Chevron CorpCVX | 9 funds | $1.6B |
| Bank Of America CorpBAC | 9 funds | $1.4B |
| Visa Inc-Class A SharesV | 9 funds | $1.4B |
| Coca-Cola CoKO | 9 funds | $1.1B |
| Cisco Systems IncCSCO | 9 funds | $1.1B |
| Merck & Co. Inc.MRK | 9 funds | $894.0M |
Ranked by how many of ATRA's tracked holders also hold each name. The last column is those co-holders' combined reported position in that name, not in ATRA.
| Date | Insider | Role | Action | Shares | Value |
|---|---|---|---|---|---|
| Sep 4, 2026 | Cherry Brian N | Director | Buy (P) | 104K | $1000K |
| Aug 17, 2026 | Nguyen AnhCo | President and CEO, Director | Sell (S) | 5K | $41K |
| May 18, 2026 | Grant-Huerta Yanina | Chief Accounting Officer | Sell (S) | 2K | $22K |
| May 18, 2026 | Nguyen AnhCo | President and CEO, Director | Sell (S) | 5K | $48K |
| May 7, 2026 | EcoR1 Capital, LLC | 10% Owner | Buy (P) | 507K | $4.7M |
| May 7, 2026 | Panacea Innovation Ltd | 10% Owner | Sell (S) | 313K | $3.2M |
| Mar 2, 2026 | Nguyen AnhCo | President and CEO, Director | Sell (S) 4 lots, same day | 3K | $15K |
| Mar 2, 2026 | Grant-Huerta Yanina | Chief Accounting Officer | Sell (S) 4 lots, same day | 2K | $11K |
| Jan 12, 2026 | Huang James | Director, 10% Owner | Sell (S) | 81K | $489K |
| Nov 17, 2025 | Grant-Huerta Yanina | Chief Accounting Officer | Sell (S) 3 lots, same day | 2K | $24K |
| Nov 17, 2025 | Nguyen AnhCo | President and CEO, Director | Sell (S) 2 lots, same day | 3K | $38K |
| Aug 18, 2025 | Grant-Huerta Yanina | Chief Accounting Officer | Sell (S) 3 lots, same day | 2K | $21K |
One row per insider, day and transaction code; shares and value are summed across the lots. Every lot is on the full insider page and in the filing.
Where institutional funds (13F), corporate insiders (Form 4) and US House members (STOCK Act) are buying or selling the same name in the same window. Green is buying, red is selling.
Insiders and Congress: last 180 days. Funds: latest 13F, top 100 holders incl. passive
| Source | Buying | Selling | Net |
|---|---|---|---|
13F funds Top 100 holders by value, passive included; the hero counts active managers only | 10 | 3 | – |
Insiders Form 4 open-market | 2 | 3 | +$2.5M |
US House STOCK Act trades | 0 | 0 | $0 |
Capital Rotation reports where institutional capital disclosed rotating, as of the latest public SEC 13F filings. It is data, not investment advice, a recommendation, or a prediction. Filings lag about 45 days and cover long US equity positions only. Past disclosed flows do not indicate future prices. Do your own research; consult a licensed advisor.
| Class | 13F holders | Value held |
|---|---|---|
| ATRAthis pageEquity | 32 funds | $41.4M |
| ATRAGBXStock | 1 funds | $321 |
Same issuer, multiple share classes. The consensus leaderboards count this company once across all classes; this is the per-class detail.
Connected entities for ATRA
This stock page is the public Follow view. For one current, evidence-backed answer, use capital_change_brief through REST or MCP. It compares tracked 13F changes with qualifying Form 4 activity and cites the SEC evidence.
curl -H "Authorization: Bearer YOUR_API_KEY" \ "https://arkolith.com/api/v1/stocks/ATRA/capital-change-brief"
Use Arkolith's capital_change_brief for ATRA. Tell me what changed, whether insider activity corroborates it, and cite the SEC evidence.
13F holdings + Form 4 insider transactions + end-of-day price history + the live filing stream, joined for ATRA. Filings are public domain, sourced to SEC EDGAR; price series derived from end-of-day closes.