Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
280 institutional managers reported holding ATRO for the quarter ended Mar 31, 2026. Together they hold about 65% of shares outstanding; the top 10 hold 29%. 48 opened new positions; 40 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| BlackRock | 2.83M | 5.90% | $188.6M | added +1% | ≤2013 |
| State Street | 2.35M | 4.91% | $156.8M | added +28.3% | ≤2013 |
| Vanguard Group | 2.01M | 4.20% | $134.2M | added +1.8% | ≤2013 |
| American Century Companies INC | 1.74M | 3.63% | $116.0M | trimmed -1.5% | 2024 Q1 |
| Capital International Investors | 1.29M | 2.69% | $86.0M | trimmed -30.3% | 2025 Q3 |
| Geode Capital | 887.0k | 1.85% | $59.2M | added +17.3% | ≤2013 |
| Pertento Partners LLP (focused) | 815.3k | 1.70% | $54.4M | opened | 2026 Q1 |
| Next Century Growth Investors LLC | 786.3k | 1.64% | $52.5M | trimmed -26.3% | 2021 Q1 |
| Dimensional Fund Advisors | 673.8k | 1.41% | $45.0M | added +5.3% | ≤2013 |
| D. E. Shaw | 608.4k | 1.27% | $40.6M | added +23.3% | 2017 Q1 |
| Point72 | 567.2k | 1.18% | $37.9M | added +14.1% | 2024 Q2 |
| Capital Group (American Funds) | 560.9k | 1.17% | $37.4M | opened | 2026 Q1 |
| Raymond James Financial INC | 492.8k | 1.03% | $32.9M | added +13.1% | 2018 Q3 |
| Goldman Sachs | 455.1k | 0.95% | $30.4M | added +44.6% | ≤2013 |
| Ameriprise Financial INC | 450.7k | 0.94% | $30.1M | added +76.1% | 2023 Q1 |
| Emerald Advisers, LLC | 449.1k | 0.94% | $30.0M | added +85% | 2025 Q4 |
| Morgan Stanley | 447.5k | 0.93% | $29.9M | trimmed -18.9% | ≤2013 |
| BNP Paribas Financial Markets | 412.0k | 0.86% | $27.5M | trimmed -7.4% | 2014 Q1 |
| Nuveen | 401.3k | 0.84% | $26.8M | trimmed -0.6% | 2019 Q2 |
| Hennessy Advisors INC | 377.8k | 0.79% | $25.2M | trimmed -3.4% | 2025 Q2 |
| Royce & Associates | 363.4k | 0.76% | $24.3M | trimmed -30.2% | 2016 Q1 |
| Fisher Investments | 348.8k | 0.73% | $23.3M | added +475.3% | 2022 Q4 |
| UBS | 340.1k | 0.71% | $22.7M | added +2.6% | 2022 Q4 |
| Driehaus Capital Management LLC | 326.5k | 0.68% | $21.8M | trimmed -51% | 2025 Q3 |
| Fred Alger Management, LLC | 325.0k | 0.68% | $21.7M | added +120.8% | 2025 Q4 |
| Private Capital Management, LLC | 322.5k | 0.67% | $21.5M | trimmed -41.9% | 2025 Q1 |
| Charles Schwab Investment Management | 288.8k | 0.60% | $19.3M | trimmed -1.4% | ≤2013 |
| Jupiter Asset Management LTD | 281.0k | 0.59% | $18.8M | opened | 2026 Q1 |
| Emerald Mutual Fund Advisers Trust | 279.2k | 0.58% | $18.6M | added +78.1% | 2025 Q4 |
| Needham Investment Management LLC | 272.5k | 0.57% | $18.2M | unchanged | 2024 Q1 |
| Northern Trust | 268.9k | 0.56% | $17.9M | added +3% | ≤2013 |
| Caspian Capital LP (focused) | 267.7k | 0.56% | $17.9M | added +17.6% | 2025 Q4 |
| Deutsche Bank AG\ | 261.6k | 0.55% | $17.5M | trimmed -37% | ≤2013 |
| First Trust Advisors LP | 253.5k | 0.53% | $16.9M | added +4.1% | 2024 Q4 |
| Marshall Wace | 251.2k | 0.53% | $16.8M | trimmed -34.8% | 2024 Q3 |
| AQR Capital | 247.3k | 0.52% | $16.5M | trimmed -4.2% | 2023 Q1 |
| Acadian Asset Management | 229.3k | 0.48% | $15.3M | added +47.6% | 2020 Q2 |
| Renaissance Technologies | 222.9k | 0.47% | $14.9M | added +320.4% | 2022 Q2 |
| Millennium Management | 220.0k | 0.46% | $14.7M | trimmed -39% | 2018 Q3 |
| Two Sigma | 216.7k | 0.45% | $14.5M | added +550.8% | 2021 Q4 |
| CPP Investment Board | 212.8k | 0.44% | $14.2M | trimmed -26.2% | 2025 Q2 |
| Jane Street | 201.1k | 0.42% | $13.4M | added +1811% | 2022 Q4 |
| Bank OF America CORP /DE/ | 199.7k | 0.42% | $13.3M | added +81.9% | ≤2013 |
| M&G PLC | 198.7k | 0.41% | $13.3M | opened | 2026 Q1 |
| First Eagle Investment Management | 192.3k | 0.40% | $12.8M | trimmed -16.5% | 2021 Q2 |
| Royal Bank OF Canada | 183.5k | 0.38% | $12.2M | trimmed -2.9% | ≤2013 |
| Invesco | 179.0k | 0.37% | $11.9M | trimmed -13% | 2016 Q1 |
| Congruence Capital, LLC (focused) | 175.4k | 0.37% | $11.7M | trimmed -51.6% | 2025 Q4 |
| Qube Research & Technologies LTD | 166.8k | 0.35% | $11.1M | added +286% | 2023 Q3 |
| Hsbc Holdings PLC | 144.2k | 0.30% | $9.6M | trimmed -2.7% | 2025 Q3 |
Largest 50 of 280 shown; the full ranked, searchable register is at boothcheck.com/holders/ATRO. Related filers are grouped using the filings' own included-manager declarations. Historically, several managers opening new positions in the same quarter said almost nothing about the quarter that followed (59,118 cases since 2013). A filed record, not a forecast. Nothing here is investment advice.