BSX
Boston Scientific Corp
6 super-investors hold BSX worth a combined $577M. The largest position: Lee Ainslie at 3.1% of their portfolio. This quarter the cohort logged 0 buys and 2 sells on the name. Cohort Conviction Score: 27 — ranked #484 of 724 scored stocks. Conviction easing: 1 fewer super-investor hold it than in 2025Q4.
Why super-investors own BSX
BSX interest within this cohort is fading, not building. John Armitage exited entirely in 2026Q1 while Stephen Mandel trimmed his already minimal 0.1% position, leaving six holders with $577M in combined exposure — though that figure is heavily skewed by Lee Ainslie, whose $263M stake at 3.1% of portfolio represents the only position with meaningful conviction. Joel Greenblatt holds a comparable dollar amount ($265M) but at just 0.2% of his larger portfolio. The cohort ownership count tells the clearest story: after reaching a peak of two holders just one quarter ago, it has already pulled back to one consistent high-conviction name in Ainslie, with the rest holding negligible or diminishing stakes.
AI-synthesized from 13F filings. Not investment advice.
Cohort owners over time
2016Q4 → 2026Q1How many of the cohort members held this stock each quarter.
Owners (6) · click any column to sort
| #↑ | Manager | % Port. | History | Value | Shares |
|---|---|---|---|---|---|
| 1 | Joel Greenblatt | 0.2% | 40q | $265M | 4,217,314 |
| 2 | Lee Ainslie | 3.1% | 11q | $263M | 4,195,089 |
| 3 | Polen Capital Management | 0.3% | 3q | $36M | 579,739 |
| 4 | Stephen Mandel | 0.1% | 2q | $7M | 104,655 |
| 5 | Dodge & Cox Funds | <0.1% | 40q | $6M | 88,885 |
| 6 | Mairs & Power Funds | <0.1% | 19q | $639K | 10,176 |
- 1Joel Greenblattport0.2%val$265M4,217,314 sh·40q held
- 2Lee Ainslieport3.1%val$263M4,195,089 sh·11q held
- 3Polen Capital Managementport0.3%val$36M579,739 sh·3q held
- 4Stephen Mandelport0.1%val$7M104,655 sh·2q held
- 5Dodge & Cox Fundsport<0.1%val$6M88,885 sh·40q held
- 6Mairs & Power Fundsport<0.1%val$639K10,176 sh·19q held
Owners of BSX also hold
Recent activity (2)
| Manager | Move | % Port. | Δ Shares | Value | Filed |
|---|---|---|---|---|---|
| Stephen Mandel | TRIM | 0.1% | -48% | $7M | May 15, 2026 |
| John Armitage | EXIT | 5.6% | -100% | $0 | May 13, 2026 |
Long US equity 13F-HR filings only. CUSIP 101137107. Not investment advice.