Company · Ownership research

CASTLE BIOSCIENCES INC CSTL

CIK 0001447362 · CUSIP 14843C105

Insider tradingInitial holdingsInstitutional holders

Quarter-end disclosures, not live holdings.

3 CUSIPs are reported under this ticker. This page covers the one most managers report; the others are not merged in.
This page lists the top 20 of 136 rows by value; the complete set is available through the API.
This is the oldest quarter open without an account, so changes against the quarter before it are withheld. Sign in to see them.
Some filings reported values in thousands; those figures were scaled ×1000 to dollars.

Top 20 institutions

Weight means this stock's share of the manager's own portfolio.

By reported value
#ManagerValueManager weightChange vs priorSource

Showing 20 / 136 institutions. The complete set is available through the API.

Coverage & totals by quarter

Reporting institutions
136
Cancelled or null records excluded
Disclosed shares
23,151,775
Not deduplicated across managers
Disclosed value
$391.03M
Not market cap or free float

Reporting institutions by quarter

Counts also change with data coverage and reporting entities; they do not measure net buying. Distinct managers with a live stock row in this CUSIP; totals may include overlapping filings and are not a share of the company.

CASTLE BIOSCIENCES INC · Q3 2023

Explore all 136 reporting institutions.

This page includes 20 of 136 reporting institutions. Sign in to look up the full history beyond 3 years, use advanced screening & filtering, download CSV, and get the complete set through the Akkru API.

  • Download CSV
  • Earlier quarters
  • Advanced screening & filtering
  • API & AI access
Already have an account?

＋ New accounts get free API credits to explore data beyond ownership filings.

For AI agents & developers

The initial HTML of this page carries its exact data as script#research-data (JSON): values, units, scope, preview limits and SEC sources. Read it directly, no script or API key needed; script#research-access says what needs an account. This page lists 20 of 136 reporting institutions; totals use the complete disclosed data.

Without an account: the last 3 years, with the row caps stated on the page. A free account opens all history on file on these pages and the CSV of what a page shows. Rows beyond the caps and bulk retrieval go through the authenticated API / MCP.

MCP  https://api.akkrudata.ai/mcp

get_institutional_security_holders
{"cusip":"14843C105","quarter":"2023Q3","type":"positions","page_size":100}

Connect to MCP with OAuth and follow the returned pagination. Credits and usage limits depend on the account.

MCP endpoint
https://api.akkrudata.ai/mcp
API / MCP documentation
/documents
llms.txt
/llms.txt
Sources, coverage & how to read this data

Figures are as reported to the SEC and merged with later amendments where Akkru could match them. Preview limits apply to what is listed, not to the totals, which come from the complete reported data. Nothing is zero-filled: a missing quarter or month is shown as missing.