Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
405 institutional managers reported holding ICLR for the quarter ended Mar 31, 2026. Reported positions total over 95% of shares outstanding; the top 10 hold 51%. 60 opened new positions; 161 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| Artisan Partners | 8.28M | 10.60% | $915.2M | added +20.4% | 2024 Q4 |
| Wellington Management | 5.91M | 7.57% | $653.6M | added +35.9% | ≤2013 |
| Harris Associates (Oakmark) | 4.35M | 5.57% | $481.0M | added +73.3% | 2025 Q2 |
| FMR (Fidelity) | 4.17M | 5.35% | $461.4M | added +34.7% | 2016 Q2 |
| Invesco | 3.88M | 4.97% | $428.8M | added +3.2% | ≤2013 |
| Principal Financial Group INC | 3.31M | 4.24% | $366.1M | added +10.3% | 2015 Q1 |
| Brave Warrior Advisors, LLC (focused) | 3.00M | 3.84% | $331.3M | opened | 2024 Q4 |
| MFS Investment Management | 2.73M | 3.49% | $301.5M | added +15.7% | 2017 Q3 |
| Sachem Head Capital Management LP (focused) | 2.10M | 2.70% | $232.7M | opened | 2026 Q1 |
| Greenhaven Associates INC (focused) | 2.00M | 2.56% | $221.3M | added +11412.1% | 2025 Q2 |
| Ruane Cunniff (Sequoia) (focused) | 1.63M | 2.09% | $180.7M | trimmed -2.7% | 2024 Q4 |
| Brandes Investment Partners, LP | 1.44M | 1.84% | $158.6M | added +84.8% | 2025 Q2 |
| AllianceBernstein | 1.34M | 1.72% | $148.6M | added +5.7% | ≤2013 |
| Madison Avenue Partners, LP (focused) | 1.28M | 1.64% | $141.8M | opened | 2026 Q1 |
| Trinity Street Asset Management LLP (focused) | 1.21M | 1.55% | $133.5M | added +12.7% | 2021 Q2 |
| D. E. Shaw | 1.20M | 1.53% | $132.5M | added +83.5% | 2023 Q4 |
| 1832 Asset Management L.p. | 1.19M | 1.53% | $131.9M | trimmed -0.9% | 2023 Q2 |
| Capital Group (American Funds) | 1.10M | 1.42% | $122.1M | trimmed -26.2% | 2025 Q3 |
| Equity Investment CORP | 1.10M | 1.40% | $121.2M | added +75.9% | 2025 Q2 |
| First Manhattan CO. LLC. | 1.00M | 1.28% | $110.7M | added +2.1% | 2021 Q3 |
| Lyrical Asset Management LP (focused) | 938.2k | 1.20% | $103.7M | trimmed -3.1% | 2025 Q4 |
| VAN Lanschot Kempen Investment Management N.v. | 918.7k | 1.18% | $101.6M | added +23.6% | 2025 Q4 |
| Earnest Partners LLC | 885.8k | 1.13% | $97.9M | unchanged | 2013 Q4 |
| Holocene Advisors | 840.8k | 1.08% | $92.9M | added +419.1% | 2022 Q4 |
| Boston Partners | 835.1k | 1.07% | $92.3M | trimmed -33.7% | ≤2013 |
| Franklin Resources | 816.1k | 1.04% | $90.2M | trimmed -72.7% | 2020 Q3 |
| Dimensional Fund Advisors | 788.8k | 1.01% | $87.2M | added +50.8% | 2021 Q3 |
| SEI Investments CO | 757.5k | 0.97% | $83.7M | trimmed -3.6% | ≤2013 |
| Lakewood Capital Management, LP | 747.7k | 0.96% | $82.7M | added +124.9% | 2025 Q2 |
| Goldman Sachs | 630.6k | 0.81% | $69.7M | added +33.3% | ≤2013 |
| UBS | 628.8k | 0.81% | $69.5M | added +14% | ≤2013 |
| Sound Shore Management INC /CT/ (focused) | 627.0k | 0.80% | $69.3M | opened | 2026 Q1 |
| Thrivent Financial for Lutherans | 622.4k | 0.80% | $68.8M | added +119.5% | 2025 Q4 |
| Stephens Investment Management Group LLC | 599.2k | 0.77% | $66.2M | added +10.3% | ≤2013 |
| Bank OF America CORP /DE/ | 543.5k | 0.70% | $60.1M | trimmed -10.9% | ≤2013 |
| Russell Investments Group, LTD. | 514.3k | 0.66% | $56.9M | added +83.1% | 2016 Q4 |
| State Street | 457.2k | 0.59% | $50.5M | added +26.6% | 2013 Q4 |
| Impactive Capital LP (focused) | 450.5k | 0.58% | $49.8M | opened | 2026 Q1 |
| Bamco INC /NY/ | 426.8k | 0.55% | $47.2M | trimmed -20.1% | ≤2013 |
| BlackRock | 413.6k | 0.53% | $45.7M | added +9.5% | ≤2013 |
| Aberdeen Group plc | 399.3k | 0.51% | $44.1M | added +504.4% | 2020 Q4 |
| River Road Asset Management, LLC | 369.7k | 0.47% | $40.9M | trimmed -22.2% | 2025 Q2 |
| Eagle Health Investments LP (focused) | 358.5k | 0.46% | $39.6M | added +45.1% | 2022 Q4 |
| NEW York State Common Retirement Fund | 345.7k | 0.44% | $38.2M | added +40.3% | ≤2013 |
| Maple Rock Capital Partners INC. (focused) | 335.3k | 0.43% | $37.1M | opened | 2026 Q1 |
| Hudson Edge Investment Partners INC. | 319.0k | 0.41% | $35.3M | added +22.5% | 2023 Q4 |
| Sio Capital Management, LLC | 306.4k | 0.39% | $33.9M | added +140.8% | 2025 Q4 |
| Morgan Stanley | 293.1k | 0.38% | $32.4M | trimmed -38.1% | ≤2013 |
| Zuckerman Investment Group, LLC | 281.0k | 0.36% | $31.1M | added +80.5% | 2024 Q4 |
| Raymond James Financial INC | 261.4k | 0.34% | $28.9M | added +36.8% | 2013 Q3 |
Largest 50 of 405 shown; the full ranked, searchable register is at boothcheck.com/holders/ICLR. 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.