Whale Analyzer
Top public holders · 13F and disclosure aggregation

Who owns BSX? 13F holders and whale ownership

BSX is tracked across public portfolios in Whale Analyzer. This page answers who owns BSX, which top funds are buying BSX, aggregate disclosed value, and recent position changes based on public data. PRIMECAP Management is the largest reported holder at $2.04B; the top five funds control 99.8% of reported ownership; institutions were net selling last quarter (2 increased, 4 reduced); the stock trades above the aggregate whale cost basis of $28.61. Top tracked holders include PRIMECAP Management, Edgewood Management, Lee Ainslie, and Samuel Isaly.

Continue to the live BSX dashboard
NYQ · latest quote
$44.23
-$1.06 (-2.3%)
Open live BSX dashboard
6Tracked holders
$2.98BAggregate reported value
2026-05-21Page updated
4 reduced, 2 increasedRecent changes

Top holders

InvestorReported valueSharesChange
PRIMECAP Management 13F portfolio
PRIMECAP Management Company holdings
$2.04B32.5MIncreased
Edgewood Management 13F portfolio
Edgewood Management LLC holdings
$478.7M7.6MReduced
Lee Ainslie 13F portfolio
Maverick Capital holdings
$263.2M4.2MIncreased
Samuel Isaly 13F portfolio
OrbiMed Advisors holdings
$149.5M2.4MReduced
Polen Capital 13F portfolio
Polen Capital Management holdings
$36.4M579.7KReduced
Stephen Mandel 13F portfolio
Lone Pine Capital holdings
$6.6M104.7KReduced

Ownership concentration

Reported ownership of BSX is highly concentrated across tracked institutions.

Whale activity this quarter

Across 6 tracked institutions, 4 reduced, 2 increased. Net positioning is net selling.

Whale cost basis vs current price

The aggregate tracked cost basis is $28.61 versus a current price of $44.23, so BSX trades above its cost basis (+54.6%). Average unrealized P&L across tracked holders: 408%.

Sector positioning — Health Care

BSX sits within the Health Care sector alongside 221 other tracked names. Compare whale ownership across peers:

How to use this page

Values are reported public positions from tracked 13F filers and disclosures — not real-time ownership totals. Open the live BSX dashboard for price charts and cross-investor scans, or read the SEC 13F guide.

This page is generated from public filings and public disclosures. It is for research and education only and is not investment advice.

Related stock holder pages

Learn more in Whale Analyzer Academy

Deepen your read on BSX with these Whale Analyzer Academy guides:

Frequently asked questions

Who owns BSX stock?

Whale Analyzer tracks 6 public institutional holders of BSX with a combined reported value of $2.98B. See the holder table above for the largest tracked positions.

Which top funds are buying BSX?

Tracked institutions were net selling last quarter — 4 reduced, 2 increased. Check the "Change" column: "New" = fresh position, "Increased" = added, "Reduced" = trimmed.

How concentrated is BSX ownership?

The top five tracked holders report 99.8% of aggregate ownership.

Is BSX above or below the whale cost basis?

The aggregate tracked cost basis is $28.61 versus a current price of $44.23 (+54.6%).

What does 13F ownership mean for BSX?

Use the interactive BSX dashboard on Whale Analyzer for real-time holder analysis, or read our 13F Alpha Signals Guide.