Company · Ownership research

CRESCENT BIOPHARMA, INC. CBIO

CIK 0001253689

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

Insider trading Initial holdings Institutional holders

Insider filings on file run through 2026-07-20.

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: $30.79M
Sold: $1.71M

Sep 1, 2023 – Jul 20, 2026
Available records · partial months are marked ·

20268 of 8 preview events

Date	Insider	Activity	Trade value (USD)	% of prior holding
2026-07-16	Harwin Peter Evan · Fairmount Healthcare Fund II L.P. · Fairmount Funds Management LLC · Kiselak Tomas Director · 10% owner	Purchase	$12.38M 853,450 shares bought	Unavailable Indirect holding	▾
2026-06-22	Lynch Ryan See Remarks	Sale10b5-1 footnote	$8.37K 465 shares sold	3.24% sold Direct holding	▾
2026-06-22	Pinkas Jan Chief Scientific Officer	Sale10b5-1 footnote	$23.17K 1,288 shares sold	5.47% sold Direct holding	▾
2026-06-22	Scalzo Richard William Chief Financial Officer	Sale10b5-1 footnote	$20.00K 1,112 shares sold	5.19% sold Direct holding	▾
2026-06-22	Bispham Barbara Harlin See Remarks	Sale10b5-1 footnote	$21.91K 1,218 shares sold	5.93% sold Direct holding	▾
2026-06-22	Im Ellie Eunkyung Chief Medical Officer	Sale10b5-1 footnote	$21.93K 1,219 shares sold	5.23% sold Direct holding	▾
2026-06-22	McNeill Jonathan President and COO	Sale10b5-1 footnote	$369.68K 20,549 shares sold	12.87% sold Direct holding	▾
2026-06-22	Brumm Joshua T Chief Executive Officer · Director	Sale10b5-1 footnote	$761.07K 42,305 shares sold	13.08% sold Direct holding	▾

Showing 8 / 8 record groups in 2026. The complete set is available through the API.

CRESCENT BIOPHARMA, INC. · CBIO

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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 8 of 8 purchase / sale groups and 6 of 6 other groups; the totals and the monthly series cover the whole window.

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

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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.