Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
652 institutional managers reported holding ATI for the quarter ended Mar 31, 2026. Together they hold about 92% of shares outstanding; the top 10 hold 49%. 154 opened new positions; 59 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| BlackRock | 16.44M | 11.86% | $2.39B | added +12.1% | ≤2013 |
| Vanguard Group | 13.00M | 9.38% | $1.89B | added +2% | ≤2013 |
| Capital Research Global Investors | 6.16M | 4.45% | $896.0M | added +70.6% | 2025 Q1 |
| Capital International Investors | 5.88M | 4.25% | $855.8M | trimmed -65.6% | 2019 Q1 |
| Capital Group (American Funds) | 5.71M | 4.12% | $830.9M | trimmed -22.3% | 2018 Q2 |
| State Street | 5.38M | 3.88% | $782.7M | trimmed -3.9% | ≤2013 |
| FMR (Fidelity) | 5.25M | 3.79% | $763.2M | added +3.4% | 2017 Q4 |
| Invesco | 3.86M | 2.78% | $560.8M | added +13.9% | ≤2013 |
| Viking Global | 3.33M | 2.40% | $484.8M | opened | 2026 Q1 |
| Geode Capital | 2.95M | 2.13% | $428.7M | added +21.8% | ≤2013 |
| Point72 | 1.93M | 1.39% | $281.1M | added +154.2% | 2017 Q3 |
| UBS | 1.77M | 1.28% | $258.0M | added +14.8% | ≤2013 |
| D. E. Shaw | 1.74M | 1.26% | $253.5M | trimmed -13.8% | ≤2013 |
| Morgan Stanley | 1.67M | 1.20% | $242.7M | added +30% | ≤2013 |
| Charles Schwab Investment Management | 1.50M | 1.08% | $218.5M | added +1% | ≤2013 |
| Jane Street | 1.49M | 1.08% | $216.9M | added +438% | 2019 Q3 |
| Dimensional Fund Advisors | 1.37M | 0.99% | $198.8M | trimmed -35.7% | ≤2013 |
| Bank OF America CORP /DE/ | 1.36M | 0.98% | $198.5M | added +70.8% | ≤2013 |
| Dendur Capital LP (focused) | 1.28M | 0.93% | $186.6M | trimmed -37.1% | 2024 Q3 |
| Northern Trust | 1.24M | 0.89% | $180.2M | added +5.5% | ≤2013 |
| AQR Capital | 1.22M | 0.88% | $177.8M | added +19.9% | 2022 Q2 |
| Arrowstreet Capital | 1.20M | 0.87% | $175.1M | added +231.4% | 2025 Q4 |
| Holocene Advisors | 1.10M | 0.79% | $159.6M | added +2.4% | 2024 Q1 |
| SG Americas Securities, LLC | 1.08M | 0.78% | $156.4M | added +1471.8% | ≤2013 |
| American Century Companies INC | 1.07M | 0.77% | $155.5M | trimmed -32.8% | 2019 Q4 |
| Bowen Hanes & CO INC | 1.04M | 0.75% | $151.7M | trimmed -11.4% | 2022 Q1 |
| Mirae Asset Global Etfs Holdings LTD. | 1.04M | 0.75% | $150.8M | added +2.3% | 2018 Q3 |
| Ameriprise Financial INC | 998.8k | 0.72% | $145.3M | trimmed -19.7% | ≤2013 |
| Fisher Investments | 924.5k | 0.67% | $134.5M | added +1.8% | 2018 Q2 |
| BNY Mellon | 869.2k | 0.63% | $126.4M | trimmed -4.8% | ≤2013 |
| Qube Research & Technologies LTD | 858.8k | 0.62% | $124.9M | added +99.6% | 2025 Q4 |
| Balyasny Asset Management | 851.7k | 0.61% | $123.9M | added +118.4% | 2025 Q4 |
| PNC Financial Services Group, INC. | 831.7k | 0.60% | $121.0M | added +1714% | ≤2013 |
| Prudential Financial INC | 810.0k | 0.58% | $117.8M | added +1.7% | ≤2013 |
| Barrow Hanley Mewhinney & Strauss LLC | 782.5k | 0.56% | $113.8M | trimmed -8.8% | 2016 Q3 |
| Artemis Investment Management LLP | 721.5k | 0.52% | $104.9M | opened | 2026 Q1 |
| Frontier Capital Management CO LLC | 694.4k | 0.50% | $101.0M | trimmed -43.4% | ≤2013 |
| BNP Paribas Financial Markets | 654.5k | 0.47% | $95.2M | added +64.6% | 2013 Q3 |
| Loomis Sayles & CO L P | 653.4k | 0.47% | $95.0M | trimmed -30.2% | 2023 Q1 |
| Raymond James Financial INC | 638.7k | 0.46% | $92.9M | trimmed -20.5% | 2015 Q1 |
| Millennium Management | 619.2k | 0.45% | $90.1M | added +22.2% | ≤2013 |
| Assenagon Asset Management S.a. | 584.0k | 0.42% | $84.9M | added +2162.1% | 2025 Q2 |
| Nuveen | 578.6k | 0.42% | $84.2M | added +5.7% | 2018 Q3 |
| Freestone Grove Partners LP | 575.9k | 0.41% | $83.8M | opened | 2026 Q1 |
| AllianceBernstein | 575.5k | 0.41% | $83.7M | added +87.8% | ≤2013 |
| Federated Hermes, INC. | 545.5k | 0.39% | $79.3M | unchanged | ≤2013 |
| Marshall Wace | 536.5k | 0.39% | $78.0M | trimmed -14.6% | 2024 Q1 |
| Allspring Global Investments Holdings, LLC | 520.2k | 0.38% | $75.7M | trimmed -13.8% | 2021 Q4 |
| Neuberger Berman Group LLC | 494.9k | 0.36% | $72.0M | trimmed -39.8% | ≤2013 |
| Bank OF Nova Scotia | 467.1k | 0.34% | $67.9M | added +92.9% | 2025 Q2 |
Largest 50 of 652 shown; the full ranked, searchable register is at boothcheck.com/holders/ATI. 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.