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$34.51 +1.21 (+3.63%) At close · Oct 27 Q2 2026 earnings call transcript
Market Cap
$1.05B
Shares
30.55M
Volume · Oct 27 295.28K Avg daily vol (3M) 397.34K

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Institutional holdings are being reconciled with SEC filings. Holder totals and changes may be incomplete until reconciliation finishes.
The Sep 30, 2026 filing window is still open — showing the latest known positions. Funds that have not filed yet carry their prior-quarter positions; a fund that filed without this stock counts as sold out. Each fund's Change is measured against its own previous reported quarter, shown in the Reported column. Pick a completed quarter in the Quarter selector below to put every fund on one quarter and see the stock-wide activity breakdown.
Holders: 179
Total Value: $658,504,915
Total Shares: 27,373,315
Showing 1–100 of 179 holdings by value · page 1 of 2

Institutional Ownership Trend

27 quarters

Holder Concentration

Across 177 13F filers
Top Holder
12.0%
Sep 2023 → Jun 2026 · range 10.3% – 12.0%
of institutional value
Top 5
36.3%
Sep 2023 → Jun 2026 · range 33.7% – 44.4%
of institutional value
Top 10
51.5%
Sep 2023 → Jun 2026 · range 48.6% – 61.7%
of institutional value
HHI
423
Sep 2023 → Jun 2026 · range 362 – 536
Broadly held

Who Holds CSTL

Last 8 quarters through Sep 30, 2026 (filing window open)

Each kind of 13F filer's share of the common shares 13F filers report. Holder type comes from regulatory records, never the filer's name; style, turnover and horizon are measured from each filer's own 13F book. The quarter selector does not change this card.

Jun 30, 2026, the newest closed quarter: 176 filers, like-for-like change -0.9%; actively managed books -2.1%; index-like books +1.8%.

Holder type Share Filers Change
Registered adviser 50.1% 88 -2.6%
Exempt adviser 2.3% 2 +3.3%
Adviser 0.6% 3 0.0%
Bank 5.8% 15 +12.8%
Insurer 6.3% 2 -1.9%
Broker-dealer 0.1% 1 +42.3%
Benefit plan 0.2% 2 +30.1%
Non-US 0.7% 7 -70.2%
Holding company 18.4% 8 +25.2%
Unknown 15.5% 48 -15.7%

The Sep 30, 2026 filing window is still open, so its bar carries the Jun 30, 2026 positions of filers that have not filed yet.

How the mix is measured

Shares are 13F common shares restated to today's split basis; options and principal amounts are left out. The change compares only filers with a 13F in both quarters and keeps each filer in its bucket of the later quarter on both sides; a filer that continues under a new CIK is compared through its successor. Holder type comes from each filer's current regulatory profile; client base and private funds come from the Form ADV roster current at each quarter end (rosters from December 2019, so an earlier quarter reads Unknown). Style, turnover, horizon and book size are measured from each filer's 13F book in the newest measured quarter, and Not measured means none was. Actively managed books are those measured systematic-like, concentrated or diversified active.

Excluded 3 holders with no observed 2026-03-31 13F and 2 holders with no observed 2026-06-30 13F. Compared across CIK changes: JANUS HENDERSON GROUP PLC continues as Jupiter Topco LLC.

Conviction and Crowding

176 13F filers, quarter ended Jun 30, 2026

Measured across every 13F filer's common-share book once the quarter's filing window closed. Crowding counts filers with high turnover or that advise private funds on Form ADV.

Conviction holders
0
0.000% of filers hold it in their top 10
Mar 31, 2026: 1
Holders above 5%
0
median weight 0.001%
Mar 31, 2026: 0
Crowding
40.4%
of shares outstanding, 92nd percentile
Mar 31, 2026: 43.2%
Private-fund advisers
34.2%
of shares outstanding
Institutional ownership
90.4%
92.8% of the estimated free float
Top 10 holders
51.5%
of 13F shares, Herfindahl 0.042
Active holders
-2.1%
like-for-like share change of active filers
5% stakes on record
4
0 13D, 4 13G (4 institutional, 0 passive, 0 exempt)
How long holders have held it value-weighted 11.8 quarters
Under 1 year 26.0% 1 to 3 years 37.0% 3 years or more 37.0% Since coverage start 0.000%

Managers in the top fifth by current three-year FundScore alpha were net buyers of $0 (0 buying, 0 selling).

Estimated Holder Cost Basis

Quarter ended Jun 30, 2026, on that quarter's share basis

Estimated, never filed: each 13F buy is costed at its quarter's average traded price and each sale keeps the average cost, so this is what holders paid on average if they traded evenly through each quarter.

Estimated avg cost
$26.70
estimated per share
Mar 31, 2026: $27.91
Quarter-end price
$23.85
implied by 13F values
Estimated gain or loss
-10.7%
price against the estimated cost
Estimated at a loss
66.4%
of costed 13F value

Estimated cost covers 62.5% of the 13F shares; positions already held when a filer's 13F history starts, or bought in a quarter without a trusted average price, have no estimate.

Shared Holders

Companies CSTL's active holders also own, quarter ended Jun 30, 2026
# Company Shared holders
1 ELUT Elutia Inc. 3
2 BDSX Biodesix Inc 3
3 LUNG Pulmonx Corp 3
4 CADL Candel Therapeutics, Inc. 3
5 SOPH SOPHiA GENETICS SA 3
6 FDMT 4D Molecular Therapeutics, Inc. 3
7 PSNL Personalis, Inc. 3
8 STOK Stoke Therapeutics, Inc. 3
9 URGN UroGen Pharma Ltd. 3
10 GPCR Structure Therapeutics Inc. 3

Shareholder Targets

13F filers that own its peers but not CSTL, quarter ended Jun 30, 2026

Found through its holder-overlap peers: ELUT, BDSX, LUNG, CADL, SOPH, FDMT, PSNL, STOK, URGN, GPCR, ORKA, ALKS, QURE, ZETA, ABVX, TWLO, AEIS, GH, UTHR, CIEN. 2,049 filers in all.

# Filer In peers
1 Avoro Capital Advisors LLC Registered adviser, Concentrated $2,166,800,955 3 held
2 WELLINGTON MANAGEMENT GROUP LLP Holding company, Diversified active $1,830,297,818 14 held
3 Capital World Investors Adviser, Diversified active $1,714,948,844 4 held
4 AMERIPRISE FINANCIAL INC Adviser, Diversified active $1,607,856,962 15 held
5 Deep Track Capital, LP Adviser, Diversified active $1,276,974,540 6 held
6 Pictet Asset Management Holding SA Unknown, Diversified active $1,000,169,119 12 held
7 TCG Crossover Management, LLC Unknown, Diversified active $800,603,958 1 held
8 Jericho Capital Asset Management L.P. Registered adviser, Diversified active $727,825,057 2 held
9 BAKER BROS. ADVISORS LP Registered adviser, Concentrated $710,703,346 3 held
10 Amundi Holding company, Index-like $703,442,650 6 held

Fund Ownership of CSTL by Fund Type

Registered funds' Form N-PORT reports for the quarter ended Jun 30, 2026

Index funds and index ETFs hold 15.05% of shares outstanding.

Fund type Of shares outstanding Shares
Index funds 3.28% 1,003,057
Index ETFs 11.77% 3,594,940
Active ETFs 2.00% 609,933
Active funds 12.98% 3,965,637
Unclassified 0.26% 79,259
All registered funds 30.29% 9,252,826
How fund types are measured

Each fund series counts once, with its latest Form N-PORT report dated inside the quarter; only long share positions count, restated to today's split basis. The fund type is the series' latest Form N-CEN answer on or before the quarter end (the index-fund box and the exchange-traded flag), never its name. Unclassified funds have no usable N-CEN; unit investment trusts are among them, so index ownership is a floor. Funds sit inside their advisers' 13F reports, so these shares overlap the 13F figures and are never added to them.

Showing 100 of 179
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Holder Value (USD) % of 13F Shares Open

Showing the top 100 of 179 holders. Create a free account to see every holder, past quarters, search, filters and CSV export.

Key facts CIK 1447362 CUSIP 14843C105 13F (30d) 30 filings 30 filers Visit website Investor relations