Mar 31, 2026 filings. Quarterly 13F reports arrive up to 45 days after quarter end; this register is filed through May 29, 2026.
1,617 institutional managers reported holding BSX for the quarter ended Mar 31, 2026. Together they hold about 87% of shares outstanding; the top 10 hold 39%. 180 opened new positions; 312 closed out. Complete ranked register from SEC 13F filings.
| manager | shares | % out | value (Mar 31, 2026 close) | change | held since |
|---|---|---|---|---|---|
| Vanguard Group | 141.35M | 9.46% | $8.87B | added +1% | ≤2013 |
| BlackRock | 131.82M | 8.82% | $8.27B | trimmed -3.1% | ≤2013 |
| FMR (Fidelity) | 74.23M | 4.96% | $4.66B | trimmed -23.8% | ≤2013 |
| State Street | 67.99M | 4.55% | $4.27B | added +3.3% | ≤2013 |
| Geode Capital | 33.29M | 2.23% | $2.09B | added +2.8% | ≤2013 |
| PRIMECAP Management | 32.53M | 2.18% | $2.04B | added +4.6% | ≤2013 |
| UBS | 28.34M | 1.90% | $1.78B | added +9.8% | ≤2013 |
| D. E. Shaw | 24.31M | 1.63% | $1.53B | added +116.1% | ≤2013 |
| Bank OF America CORP /DE/ | 22.76M | 1.52% | $1.43B | trimmed -9.4% | ≤2013 |
| Morgan Stanley | 22.27M | 1.49% | $1.40B | trimmed -3% | ≤2013 |
| Goldman Sachs | 18.89M | 1.26% | $1.19B | added +14.1% | ≤2013 |
| Wellington Management | 18.83M | 1.26% | $1.18B | added +94% | ≤2013 |
| Bollard Group LLC | 18.53M | 1.24% | $1.16B | trimmed -2.5% | ≤2013 |
| Janus Henderson | 16.50M | 1.10% | $1.04B | added +31% | ≤2013 |
| Capital Group (American Funds) | 15.31M | 1.02% | $960.5M | trimmed -43.6% | 2023 Q3 |
| Franklin Resources | 14.50M | 0.97% | $909.7M | added +155.4% | 2019 Q1 |
| Amundi | 14.12M | 0.94% | $886.1M | added +13.8% | 2015 Q1 |
| Arrowstreet Capital | 13.89M | 0.93% | $871.6M | added +25.9% | 2020 Q1 |
| Northern Trust | 13.37M | 0.90% | $839.1M | trimmed -4% | ≤2013 |
| DZ Bank AG Deutsche Zentral Genossenschafts Bank, Frankfurt am Main | 13.23M | 0.89% | $830.0M | trimmed -28.6% | 2016 Q4 |
| BNP Paribas Financial Markets | 12.11M | 0.81% | $760.0M | added +9.3% | ≤2013 |
| Nuveen | 11.73M | 0.79% | $736.2M | added +25.2% | ≤2013 |
| MFS Investment Management | 11.00M | 0.74% | $689.9M | added +21% | 2018 Q3 |
| Legal & General Group PLC | 10.60M | 0.71% | $665.1M | trimmed -2.5% | ≤2013 |
| Assenagon Asset Management S.a. | 10.06M | 0.67% | $631.0M | added +133.6% | 2016 Q4 |
| BNY Mellon | 9.54M | 0.64% | $598.8M | trimmed -15% | ≤2013 |
| Two Sigma | 9.41M | 0.63% | $590.5M | added +280.8% | 2019 Q4 |
| Charles Schwab Investment Management | 9.17M | 0.61% | $575.3M | added +2.5% | ≤2013 |
| Invesco | 9.05M | 0.60% | $567.9M | trimmed -32% | ≤2013 |
| CPP Investment Board | 8.04M | 0.54% | $504.2M | added +17.1% | ≤2013 |
| Parnassus Investments | 8.00M | 0.54% | $502.2M | added +1.3% | 2021 Q1 |
| Vontobel Holding LTD. | 7.98M | 0.53% | $500.6M | added +112% | 2017 Q2 |
| T. Rowe Price | 7.87M | 0.53% | $494.0M | added +5.6% | ≤2013 |
| Edgewood Management | 7.63M | 0.51% | $478.7M | trimmed -2.2% | 2025 Q2 |
| Farallon Capital | 7.47M | 0.50% | $468.7M | unchanged | 2020 Q3 |
| Ninety One UK LTD | 7.31M | 0.49% | $458.5M | added +34.2% | 2022 Q2 |
| 1832 Asset Management L.p. | 7.25M | 0.48% | $455.0M | added +229.4% | 2020 Q2 |
| Schroder Investment Management Group | 7.25M | 0.48% | $455.0M | trimmed -13.1% | ≤2013 |
| Capital Research Global Investors | 7.08M | 0.47% | $444.3M | unchanged | 2024 Q1 |
| Neuberger Berman Group LLC | 7.07M | 0.47% | $443.8M | added +76.4% | ≤2013 |
| Deutsche Bank AG\ | 6.65M | 0.45% | $417.4M | trimmed -1.4% | ≤2013 |
| Royal Bank OF Canada | 6.27M | 0.42% | $393.6M | added +13% | ≤2013 |
| Dimensional Fund Advisors | 6.10M | 0.41% | $382.6M | added +6.3% | ≤2013 |
| Ameriprise Financial INC | 5.57M | 0.37% | $349.7M | trimmed -13.3% | ≤2013 |
| Qube Research & Technologies LTD | 5.57M | 0.37% | $349.5M | added +1.2% | 2022 Q4 |
| AQR Capital | 5.24M | 0.35% | $328.7M | added +377.3% | ≤2013 |
| Pictet Asset Management Holding SA | 5.12M | 0.34% | $321.2M | added +19.1% | ≤2013 |
| Barclays PLC | 5.02M | 0.34% | $315.2M | added +15.2% | ≤2013 |
| First Manhattan CO. LLC. | 4.91M | 0.33% | $308.1M | added +161% | 2018 Q3 |
| Lazard Asset Management LLC | 4.88M | 0.33% | $306.2M | added +24.8% | 2018 Q2 |
Largest 50 of 1,617 shown; the full ranked, searchable register is at boothcheck.com/holders/BSX. 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.