Company · Ownership research

BERKLEY W R CORP WRB

CIK 0000011544

Form 4 transactions dated Sep 1, 2023 to Sep 23, 2026, as reported to the SEC.

Insider trading Initial holdings Institutional holders

This page lists 30 of 41 rows; the complete set is available through the API.

Insider filings on file run through 2026-08-05.

Some filings are submitted jointly by several insiders. The SEC form does not apportion the reported figures between them, so results include every joint filer.

Insider purchases & sales

Purchased: $705.46M
Sold: $0.00

Sep 1, 2023 – Aug 5, 2026
Available records · partial months are marked ·

202610 of 30 preview events · 41 available in 2026

Date	Insider	Activity	Trade value (USD)	% of prior holding
2026-03-03	MITSUI SUMITOMO INSURANCE CO LTD · MS&AD Insurance Group Holdings, Inc. 10% owner	Purchase10b5-1 footnote	$8.10M 112,176 shares bought	Unavailable Direct holding	▾
2026-03-02	MITSUI SUMITOMO INSURANCE CO LTD · MS&AD Insurance Group Holdings, Inc. 10% owner	Purchase10b5-1 footnote	$10.65M 146,000 shares bought	Unavailable Direct holding	▾
2026-02-27	MITSUI SUMITOMO INSURANCE CO LTD · MS&AD Insurance Group Holdings, Inc. 10% owner	Purchase10b5-1 footnote	$10.53M 147,000 shares bought	Unavailable Direct holding	▾
2026-02-26	MITSUI SUMITOMO INSURANCE CO LTD · MS&AD Insurance Group Holdings, Inc. 10% owner	Purchase10b5-1 footnote	$10.97M 153,000 shares bought	Unavailable Direct holding	▾
2026-02-25	MITSUI SUMITOMO INSURANCE CO LTD · MS&AD Insurance Group Holdings, Inc. 10% owner	Purchase10b5-1 footnote	$12.06M 168,868 shares bought	Unavailable Direct holding	▾
2026-02-24	MITSUI SUMITOMO INSURANCE CO LTD · MS&AD Insurance Group Holdings, Inc. 10% owner	Purchase10b5-1 footnote	$11.67M 164,786 shares bought	Unavailable Direct holding	▾
2026-02-23	MITSUI SUMITOMO INSURANCE CO LTD · MS&AD Insurance Group Holdings, Inc. 10% owner	Purchase10b5-1 footnote	$15.65M 220,000 shares bought	Unavailable Direct holding	▾
2026-02-20	MITSUI SUMITOMO INSURANCE CO LTD · MS&AD Insurance Group Holdings, Inc. 10% owner	Purchase10b5-1 footnote	$11.37M 160,582 shares bought	Unavailable Direct holding	▾
2026-02-19	MITSUI SUMITOMO INSURANCE CO LTD · MS&AD Insurance Group Holdings, Inc. 10% owner	Purchase10b5-1 footnote	$24.37M 345,000 shares bought	Unavailable Direct holding	▾
2026-02-18	MITSUI SUMITOMO INSURANCE CO LTD · MS&AD Insurance Group Holdings, Inc. 10% owner	Purchase10b5-1 footnote	$20.13M 285,000 shares bought	Unavailable Direct holding	▾

Showing 30 / 41 record groups in 2026. The complete set is available through the API.

BERKLEY W R CORP · WRB

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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. For the year shown, this page lists 30 of 41 purchase / sale groups and 18 of 18 other groups; the totals and the monthly series cover the whole window.

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.

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{"ticker":"WRB","transaction_code":["P","S"],"transaction_form_type":"4","page_size":20}

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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.

Non-cancelled, non-derivative purchase (P) and sale (S) rows dated inside the public window, as reported. Includes open-market and private transactions. Data after the latest filing is not asserted complete and is not zero-filled. A grouped event shares filing, transaction date, security, code, direction, ownership bucket and source. Derivative groups also match underlying security, exercise price, exercise/expiration dates and footnote references. Reported rows are retained; P/S price lots can be grouped. Post-transaction balances are never summed.