Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
886 institutional managers reported holding ACGL for the quarter ended Mar 31, 2026. Together they hold about 86% of shares outstanding; the top 10 hold 46%. 100 opened new positions; 118 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| Vanguard Group | 40.96M | 11.39% | $3.93B | trimmed -0.9% | ≤2013 |
| BlackRock | 31.35M | 8.72% | $3.01B | trimmed -1.2% | ≤2013 |
| Artisan Partners | 22.67M | 6.30% | $2.18B | trimmed -2.5% | ≤2013 |
| Bamco INC /NY/ | 16.71M | 4.64% | $1.60B | trimmed -7.1% | ≤2013 |
| State Street | 16.25M | 4.52% | $1.56B | trimmed -1.2% | ≤2013 |
| WCM Investment Management | 12.60M | 3.50% | $1.21B | trimmed -5.1% | 2023 Q1 |
| Geode Capital | 10.59M | 2.94% | $1.02B | added +1.1% | ≤2013 |
| UBS | 5.11M | 1.42% | $490.1M | added +7.7% | ≤2013 |
| Northern Trust | 4.47M | 1.24% | $429.3M | trimmed -3.5% | ≤2013 |
| Morgan Stanley | 4.26M | 1.18% | $408.9M | trimmed -0.7% | ≤2013 |
| Dimensional Fund Advisors | 4.17M | 1.16% | $400.6M | added +2.9% | ≤2013 |
| Madison Asset Management, LLC | 4.08M | 1.13% | $391.3M | trimmed -5.9% | ≤2013 |
| Invesco | 4.06M | 1.13% | $389.6M | added +5.1% | ≤2013 |
| Allspring Global Investments Holdings, LLC | 3.63M | 1.01% | $348.6M | trimmed -0.9% | 2021 Q4 |
| Royal Bank OF Canada | 3.53M | 0.98% | $339.0M | added +4.7% | ≤2013 |
| Polar Capital Holdings PLC | 3.30M | 0.92% | $316.7M | trimmed -0.9% | ≤2013 |
| Principal Financial Group INC | 3.29M | 0.92% | $316.0M | trimmed -27.6% | ≤2013 |
| Legal & General Group PLC | 3.29M | 0.91% | $315.6M | added +11.7% | ≤2013 |
| Marshfield Associates (focused) | 3.05M | 0.85% | $292.9M | added +5.7% | ≤2013 |
| Goldman Sachs | 2.86M | 0.80% | $274.5M | trimmed -3.1% | ≤2013 |
| AQR Capital | 2.73M | 0.76% | $262.2M | added +2.3% | 2014 Q4 |
| First Trust Advisors LP | 2.63M | 0.73% | $252.1M | added +319.5% | ≤2013 |
| Natixis Advisors, LLC | 2.57M | 0.71% | $246.4M | added +8.3% | ≤2013 |
| Cooke & Bieler LP | 2.24M | 0.62% | $214.8M | trimmed -15.1% | 2025 Q3 |
| Envestnet Asset Management INC | 2.22M | 0.62% | $213.3M | added +6.2% | ≤2013 |
| Charles Schwab Investment Management | 2.15M | 0.60% | $206.3M | added +5% | ≤2013 |
| BNP Paribas Financial Markets | 2.12M | 0.59% | $203.1M | unchanged | ≤2013 |
| Jones Financial Companies Lllp | 2.11M | 0.59% | $202.9M | added +22038.8% | 2023 Q3 |
| Boston Partners | 2.09M | 0.58% | $200.9M | opened | 2026 Q1 |
| Deutsche Bank AG\ | 2.02M | 0.56% | $193.7M | trimmed -7.1% | 2013 Q3 |
| Amundi | 1.96M | 0.55% | $188.1M | trimmed -0.7% | 2017 Q4 |
| Arrowstreet Capital | 1.91M | 0.53% | $183.3M | added +50.6% | 2025 Q3 |
| Swedbank Robur | 1.88M | 0.52% | $180.9M | trimmed -1.6% | 2021 Q1 |
| Nuveen | 1.85M | 0.51% | $177.5M | trimmed -26% | 2019 Q2 |
| High Ground Investment Management LLP (focused) | 1.79M | 0.50% | $172.2M | trimmed -1% | 2023 Q4 |
| Brandes Investment Partners, LP | 1.77M | 0.49% | $170.1M | added +3.6% | 2024 Q2 |
| Robeco Institutional Asset Management B.v. | 1.77M | 0.49% | $170.1M | added +14.5% | ≤2013 |
| Bank OF America CORP /DE/ | 1.74M | 0.48% | $167.2M | unchanged | ≤2013 |
| BNY Mellon | 1.72M | 0.48% | $165.4M | trimmed -2.2% | ≤2013 |
| FMR (Fidelity) | 1.71M | 0.48% | $164.3M | added +5.5% | ≤2013 |
| GQG Partners | 1.65M | 0.46% | $158.0M | trimmed -2.8% | 2025 Q1 |
| SEI Investments CO | 1.62M | 0.45% | $155.5M | trimmed -6.5% | ≤2013 |
| Fiduciary Management INC /WI/ | 1.46M | 0.41% | $140.2M | added +31.4% | 2025 Q4 |
| Barclays PLC | 1.36M | 0.38% | $130.8M | added +4.1% | ≤2013 |
| Capital International Investors | 1.35M | 0.38% | $129.8M | trimmed -29.5% | 2023 Q2 |
| Thrivent Financial for Lutherans | 1.31M | 0.36% | $126.2M | trimmed -17.8% | 2018 Q2 |
| Hsbc Holdings PLC | 1.29M | 0.36% | $123.4M | added +230% | ≤2013 |
| Two Sigma | 1.27M | 0.35% | $122.2M | trimmed -27.7% | 2023 Q2 |
| Champlain Investment Partners, LLC | 1.26M | 0.35% | $121.2M | trimmed -4.8% | 2025 Q1 |
| Wells Fargo & COMPANY/MN | 1.19M | 0.33% | $114.2M | trimmed -2.4% | ≤2013 |
Largest 50 of 886 shown; the full ranked, searchable register is at boothcheck.com/holders/ACGL. 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.