CBIO Insider Trading

Crescent Biopharma, Inc. (CBIO) operates in the Healthcare sector, specifically the Biotechnology industry, with a market capitalization near $479.5M, listed on NASDAQ, employing roughly 44 people, carrying a beta of 1.26 to the broader market. Crescent Biopharma, Inc. Led by Joshua T. Brumm, public since 2014-01-10.

In the last 12 months, Crescent Biopharma, Inc. insiders made 4 buy transactions and 16 sale transactions.

DateNameTypeSharesPriceValue
Sep 18, 2026Lynch RyanS-Sale240$17.90$4.3K
Sep 18, 2026Pinkas JanS-Sale658$17.90$11.8K
Sep 18, 2026Im Ellie EunkyungS-Sale623$17.90$11.2K
Sep 18, 2026Scalzo Richard WilliamS-Sale568$17.90$10.2K
Sep 18, 2026Bispham Barbara HarlinS-Sale620$17.90$11.1K
Sep 18, 2026Brumm Joshua TS-Sale1,610$17.90$28.8K
Sep 18, 2026Brumm Joshua TS-Sale7,837$16.71$131.0K
Sep 18, 2026McNeill JonathanS-Sale731$17.90$13.1K
Sep 18, 2026McNeill JonathanS-Sale3,839$16.71$64.1K
Jul 20, 2026Fairmount Funds Management LLCP-Purchase853,450$14.50$12.4M

CBIO Insider Activity by Quarter

Reported Form 4 and Form 5 lines under CBIO's own SEC company ID, by transaction date, back to Q4 2024. Purchases and sales are code P / S (open market or private) in the company's shares; other lines are purchases and sales of other securities (options, warrants, preferred), awards, exercises, tax withholding, gifts and other acquisitions and dispositions. Later filings and amendments can change the current quarter. Earlier quarters are not shown: the filings read reach back to Mar 28, 2018, and a quarter counts only when every filing for it was read. 203 lines filed under another SEC company ID are not counted.

QuarterPurchasesBoughtSalesSoldOther Lines
Q4 2026 (so far)0N/A0N/A0
Q3 20261$12.4M9$285.5K1
Q2 20260N/A7$1.2M5
Q1 20260N/A0N/A0
Q4 20251$18.2M0N/A27
Q3 20250N/A0N/A1
Q2 20250N/A0N/A5
Q1 20250N/A0N/A0
Q4 20240N/A0N/A0

Filings Under Another SEC Company ID

203 filing lines on file were filed under an SEC company ID (CIK) other than CBIO's (1253689). Such a filing can be a predecessor company's (one that reorganized, redomiciled or converted files under a new CIK), a former holder of the CBIO ticker's, or another company's that CBIO or its insiders report holding; the CIK alone does not say which. They are not counted in the figures above.

CIKLinesDatesSecurities
1124105203Mar 6, 2018 to Oct 27, 2023Common Stock, Series X Convertible Preferred Stock, Series Y Preferred Stock

CBIO Institutional Ownership (13F)

As of Jun 30, 2026 (Q2 2026), 82 institutions reported holding 29,586,731 CBIO shares, valued at $532.6M as reported, 94.0% of its market cap (market cap of Jun 26, 2026). That is +19 institutions from the quarter before. Among managers whose reports for both quarters are comparable, 31 opened a position, 12 closed one, 17 added and 15 trimmed.

Top Holders, Q2 2026

ManagerSharesValueChange
FMR LLC4,133,514$74.4MUnchanged
BVF INC/IL2,748,763$49.5MUnchanged
Fairmount Funds Management LLC2,747,866$49.5MUnchanged
Venrock Adviser, LLC2,133,576$38.4MUnchanged
Logos Global Management LP1,900,000$34.2M+1,417,500
FCPM III SERVICES B.V.1,677,852$30.2MUnchanged
Balyasny Asset Management L.P.1,662,917$29.9M+152,884
Vestal Point Capital, LP1,630,000$29.3M+130,000
Opaleye Management Inc.1,319,351$23.7M+6,736
BlackRock, Inc.1,271,762$22.9M+1,156,037

By Quarter

QuarterInstitutionsSharesValue
Q2 20268229,586,731$532.6M
Q1 20266325,949,547$476.6M
Q4 20255824,116,354$285.9M
Q3 20254111,318,902$134.6M
Q2 20253010,751,780$173.5M

From the SEC's Form 13F data sets: investment managers with $100 million or more in Section 13(f) securities report their holdings each quarter, up to 45 days after it ends; a restated filing replaces the original, and values are as the managers reported them (a position whose price runs about 1,000 times below other managers', from a manager whose positions mostly do, is read as reported in thousands of dollars). The same shares can be reported by more than one manager, so totals can count some twice.

ETFs Holding CBIO

FundWeight of CBIOShares (as reported)Value (as reported)Source updated
VTI Vanguard Morningstar Total Stock Market ETF0.00%906,646$15.1MOct 7, 2026
IWM iShares Russell 2000 ETF0.01%748,586$10.1MOct 8, 2026
XBI State Street SPDR S&P Biotech ETF0.05%336,968$4.6MOct 8, 2026
IWO iShares Russell 2000 Growth ETF0.03%270,843$3.7MOct 8, 2026
VTWO Vanguard Russell 2000 ETF0.01%123,941$2.1MOct 7, 2026
VXF Vanguard Extended Market ETF0.00%83,801$1.4MOct 7, 2026
IWC iShares Micro-Cap ETF0.09%91,941$1.2MOct 8, 2026
VHT Vanguard Health Care ETF0.00%62,512$1.0MOct 7, 2026
VTWG Vanguard Russell 2000 Growth ETF0.02%23,450$389.3KOct 7, 2026
BBC Virtus Biotech Clinical Trials ETF0.58%17,708$238.9KOct 8, 2026
LABU Direxion Daily S&P Biotech Bull 3X Shares0.01%15,546$209.7KOct 8, 2026
RSSL Global X - Russell 2000 ETF0.01%13,800$187.3KOct 7, 2026
IWV iShares Russell 3000 ETF0.00%11,600$156.5KOct 8, 2026
DFSU Dimensional - US Sustainability Core 1 ETF0.00%2,673$36.1KOct 8, 2026
VTHR Vanguard Russell 3000 ETF0.00%1,832$30.4KOct 7, 2026

From each fund's latest holdings file on record that shows CBIO's listed security itself. A file counts when its line count is consistent with the fund's reported holdings count (at most twice it plus 10, or at most 1,000 lines for a reported count of exactly 10, which the data source gives many funds as a cap), read with that file or inherited from the fund's last classified file (within 20% of its line count, read within 60 days). Funds whose line for the company could not be confirmed as CBIO's listed security, or that hold it through underlying funds (look-through), are not listed. Only long positions count: a fund is left out when any of its lines for CBIO reports a negative weight, share count or value, or none of them above zero (a short position, or figures that disagree). Shares, value and weight are as reported in each fund's file, dated by the data source's last update of that file (not the date of the positions); the weight is CBIO's share of that fund.

How to Read CBIO Insider Activity

Net insider sentiment skews to the sell side over the trailing twelve months: 16 sales versus 4 buys. Insider sales carry less informational weight than buys because they are often driven by liquidity, tax planning, or pre-scheduled Rule 10b5-1 trading plans rather than negative information. The transaction type alone does not say whether a sale was made on the open market or privately, or under a 10b5-1 plan; the filing's plan checkbox and footnotes do. The transaction table above includes the filer's reporting name, transaction type, share count, per-share price, and total dollar value where computable. For options traders, insider activity is one input to event-driven sizing alongside earnings calendar, analyst-rating cluster moves, and the implied-vol surface. Form 4 filings (the dominant Section 16 reporting form) must be submitted within two business days of the transaction; clusters of buys across multiple insiders within a short window are the strongest informational pattern. SEC EDGAR carries the underlying source filings for verification and additional historical depth.

Learn how insider trading is reported and how to read the data →

Frequently asked CBIO insider trading questions

How active are CBIO insiders right now?
Over the trailing twelve months, Crescent Biopharma, Inc. (CBIO) insiders made 4 buy transactions and 16 sale transactions. Net insider sentiment over the trailing twelve months tilts to the sell side (16 sales vs 4 buys). The transaction list above shows the most recent filings; each entry includes the insider's name, transaction type, share count, and per-share price.
What counts as an insider transaction?
Section 16 of the Securities Exchange Act requires officers, directors, and 10% beneficial-owner shareholders to disclose changes in their holdings via Form 3 (initial statement), Form 4 (subsequent transactions, filed within two business days), and Form 5 (annual catch-up). Insider transactions cover open-market purchases and sales, exercise of stock options, gifts, and grants. The "transaction type" field on each row distinguishes these subcategories.
Are CBIO insider buys a bullish signal?
Insider purchases (Type P, made on the open market or privately; the code covers both) carry more informational weight than insider sales: an insider must commit personal capital, and the SEC scrutinizes purchases under Rule 10b5-1 for material non-public information. Sales, by contrast, are often driven by liquidity, tax planning, or pre-scheduled 10b5-1 trading plans rather than negative information. Cluster buying (multiple insiders buying within a short window) is a stronger signal than isolated buys.
How do CBIO insider transactions affect options pricing?
Insider transaction data does not directly drive implied volatility, but Form 4 disclosures can move single-name IV if the size or timing is unusual (e.g. a large CEO buy ahead of an earnings window). Options markets price the marginal informational content; routine transactions under pre-scheduled plans are typically ignored. For event-driven options sizing, pair the insider transaction history with the upcoming earnings calendar.