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COGTCogent Biosciences, Inc. · Insider ownership research

Cogent Biosciences, Inc. insiders sold $13.9M in the past 12 months. How much of their stake is that?

Insiders sold $13.9M in the past 12 months.12% was sold under disclosed trading plans, 88% with no plan disclosed. The largest seller, John Robinson (Chief Scientific Officer), sold $3.5M. 13% of these sales were shares from exercising options.Share-of-stake figures for this company are being verified and will be added when that check is finished. Why

Updated Oct 13, 2026 from SEC filings · covers Oct 14, 2025 to Oct 13, 2026
$12.2M
sold with no plan disclosed, past 12 months
12%
of sales were under disclosed trading plans, past 12 months
5 of 12
officers and directors sold shares, past 12 months
Is this normal? More than usual: $13.9M sold, after almost none in the past 5 years. 5 insiders sold; the average is 0 a year. Year by year
Latest filing: Filed Aug 31 for a sale on Aug 27. Arlene Morris sold 46K shares ($1.7M) under a disclosed plan. Filing
SEC ownership filings: 24 filed in the 12 months to Oct 13, 2026; 248 on record since Mar 28, 2018 · See the evidence

What stands out

Four officers sold $12.2M with no disclosed plan: John Robinson ($3.5M), Jessica Sachs ($3.2M) and John Green ($3.0M), plus 1 more. The filings don't state a reason.John Robinson: largest such sale, Dec 26, 2025 · Jessica Sachs: largest such sale, Dec 26, 2025 · John Green: largest such sale, Dec 26, 2025
Outside holder Fairmount Funds Management LLC, a 10% owner and not part of management, sold $370M of stock.Largest sale, Mar 31, 2026
Tax withholding outweighed market sales: the company withheld $40.5M of officers' and directors' shares for taxes, against $13.9M sold on the open market. The largest was Andrew Robbins ($14.5M withheld).Largest withholding, Dec 17, 2025

A share of stake is shown for 0 of the 5 officers and directors who sold. 12 are left out

i
Left out: Cole Pinnow, John Green, Jessica Sachs, Karen Ferrante, Arlene Morris, Matthew Ros, Christopher Cain, Peter Harwin, Andrew Robbins, Todd Shegog, John Robinson and Evan Kearns (share of stake is being verified).
Disclosed company stock is not an insider's whole wealth.

Who sold, and how much of their stake

Officers and directors, past 12 months. Their share of stake is being verified and is not shown yet; amounts and trading plans are below.

John Robinson
Chief Scientific Officer
Not confirmed
Share of stake not shown: share of stake is being verified. Why
$3.5MNo plan disclosed
Jessica Sachs
Chief Medical Officer
Not confirmed
Share of stake not shown: share of stake is being verified. Why
$3.2MNo plan disclosed
John Green
Chief Financial Officer
Not confirmed
Share of stake not shown: share of stake is being verified. Why
$3.0MNo plan disclosed
Evan Kearns
Chief Legal Officer
Not confirmed
Share of stake not shown: share of stake is being verified. Why
$2.5MNo plan disclosed
Arlene Morris
Director
Not confirmed
Share of stake not shown: share of stake is being verified. Why
$1.7MDisclosed plan
Amounts, filings and trading plans for each seller

Selling by month

Officers and directors, Oct 2025 to Oct 2026. Each sale is counted once: under a disclosed plan, else to cover taxes, else no plan disclosed.

Disclosed planNo plan disclosedOne dollar scale for every month; the tallest bar is labeled
OctNovDec 2025: $12.2M no plan disclosed$12.2MDecJanFebMarAprMayJunJulAug 2026: $1.7M under a disclosed planAugSepOct

Recent activity

Past 30 days, Sep 14, 2026 to Oct 13, 2026

No officer or director trades were reported for the past 30 days. The most recent before that:

Aug 27, 2026Arlene Morris sold 46K shares ($1.7M) under a disclosed trading plan. 46K shares came in from vesting or option exercises the same day, so the holding rose by 0 net.
WhoSharesPrice% of total stakeTotal stake afterTrade dateFiled
Arlene Morris
Director
45,510$37.12n/an/aAug 27, 2026Aug 31, 2026

Outside holders, reported separately

Fairmount Funds Management LLC sold $370M in the past 12 months. Large shareholders and the funds or companies that board members represent are not part of management, so they are left out of the figures above.

Details

Common questions

Is the Cogent Biosciences, Inc. CEO selling stock?

No. Andrew Robbins reported no open-market sales in the past 12 months.

Why are Cogent Biosciences, Inc. insiders selling?

Filings rarely give a reason, and we don't guess at one. What they show is how the sales were made: 12% of sales by value ran under 10b5-1 trading plans disclosed in the filings and 88% had no disclosed plan. A trading plan schedules sales in advance.

Are any Cogent Biosciences, Inc. insiders buying?

No. Officers and directors reported no purchases in the past 12 months.

The evidence

Who sold5 officers and directors: amount, % of holdings, trading plan
Who soldAmount% of holdingsTrading plan
John Robinson
Chief Scientific Officer
$3.5M
90K shares
Not confirmed
share of stake is being verified. Why
No plan disclosed
Jessica Sachs
Chief Medical Officer
$3.2M
83K shares
Not confirmed
share of stake is being verified. Why
No plan disclosed
John Green
Chief Financial Officer
$3.0M
77K shares
Not confirmed
share of stake is being verified. Why
No plan disclosed
Evan Kearns
Chief Legal Officer
$2.5M
65K shares
Not confirmed
share of stake is being verified. Why
No plan disclosed
Arlene Morris
Director
$1.7M
46K shares
Not confirmed
share of stake is being verified. Why
Disclosed plan

Outside holder, reported separately: Fairmount Funds Management LLC (an outside shareholder, not part of management). Sold $370M (10.50M shares) from Jan 22, 2026 to Mar 31, 2026. Latest filing

The full ownership picture0 of 12 officers and directors confirmed

Vested shares across all share classes, held directly and through trusts, LLCs and family members, as reported on SEC Forms 3, 4 and 5. Unvested awards and options are never counted as owned shares.

InsiderHeld Oct 13, 2025SoldHeld Oct 13, 2026Still held
Cole Pinnow
!
Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Cole Pinnow are complete.
Chief Commercial Officer
n/a0n/an/a
Vesting, gifts, unvested awards and holding lines for Cole Pinnow

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Cole Pinnow are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)
−95Kwithheld by the company for taxes

Stock options (not counted as shares):

Options heldStrike priceExpiresIntrinsic value (estimate)
525,000$8.22May 25, 2034$15.4M
240,000$8.89Jan 23, 2035$6.9M
65,000$39.45Dec 17, 2035$0

Estimate: options held × ($37.54 − strike price), using the most recent insider trade price on Form 4 (Aug 27, 2026), not a market close.

John Green
!
Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for John Green are complete.
Chief Financial Officer
n/a−77Kn/an/a
Vesting, gifts, unvested awards and holding lines for John Green

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for John Green are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)
−145Kwithheld by the company for taxes

Stock options (not counted as shares):

Options heldStrike priceExpiresIntrinsic value (estimate)
300,000$4.63Jan 23, 2034$9.9M
270,000$8.89Jan 23, 2035$7.7M
65,000$39.45Dec 17, 2035$0

Estimate: options held × ($37.54 − strike price), using the most recent insider trade price on Form 4 (Aug 27, 2026), not a market close.

Jessica Sachs
!
Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. See the filing Sales and other transactions for Jessica Sachs are complete.
Chief Medical Officer
n/a−83Kn/an/a
Vesting, gifts, unvested awards and holding lines for Jessica Sachs

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Jessica Sachs are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)
−155Kwithheld by the company for taxes

Stock options (not counted as shares):

Options heldStrike priceExpiresIntrinsic value (estimate)
300,000$4.63Jan 23, 2034$9.9M
270,000$8.89Jan 23, 2035$7.7M
65,000$39.45Dec 17, 2035$0

Estimate: options held × ($37.54 − strike price), using the most recent insider trade price on Form 4 (Aug 27, 2026), not a market close.

Karen Ferrante
!
Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Karen Ferrante are complete.
Director
n/a0n/an/a
Vesting, gifts, unvested awards and holding lines for Karen Ferrante

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Karen Ferrante are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options heldStrike priceExpiresIntrinsic value (estimate)
3,298$6.24Jan 2, 2034$103K
3,213$6.90Apr 1, 2034$98K
44,700$8.92Jun 5, 2034$1.3M
2,462$8.94Jul 1, 2034$70K
2,034$10.75Oct 1, 2034$54K
2,785$7.80Jan 1, 2035$83K
3,788$5.79Apr 1, 2035$120K
44,700$5.64Jun 4, 2035$1.4M
3,314$7.22Jul 1, 2035$100K
1,642$14.13Oct 1, 2035$38K
643$34.74Jan 1, 2036$2K
686$35.24Apr 1, 2036$2K
17,901$31.98Jun 9, 2036$100K
627$38.48Jul 1, 2036$0
759$31.59Oct 1, 2036$5K

Estimate: options held × ($37.54 − strike price), using the most recent insider trade price on Form 4 (Aug 27, 2026), not a market close.

Arlene Morris
!
Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Arlene Morris are complete.
Director
n/a−46Kn/an/a
Vesting, gifts, unvested awards and holding lines for Arlene Morris

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Arlene Morris are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options heldStrike priceExpiresIntrinsic value (estimate)
44,700$8.92Jun 5, 2034$1.3M
2,773$5.64Jun 4, 2035$88K
17,901$31.98Jun 9, 2036$100K

Estimate: options held × ($37.54 − strike price), using the most recent insider trade price on Form 4 (Aug 27, 2026), not a market close.

Matthew Ros
!
Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Matthew Ros are complete.
Director
n/a0n/an/a
Vesting, gifts, unvested awards and holding lines for Matthew Ros

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Matthew Ros are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options heldStrike priceExpiresIntrinsic value (estimate)
3,051$6.24Jan 2, 2034$95K
44,700$8.92Jun 5, 2034$1.3M
44,700$5.64Jun 4, 2035$1.4M
17,901$31.98Jun 9, 2036$100K

Estimate: options held × ($37.54 − strike price), using the most recent insider trade price on Form 4 (Aug 27, 2026), not a market close.

Christopher Cain
!
Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Christopher Cain are complete.
Director
n/a0n/an/a
Vesting, gifts, unvested awards and holding lines for Christopher Cain

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Christopher Cain are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options heldStrike priceExpiresIntrinsic value (estimate)
44,700$8.92Jun 5, 2034$1.3M
44,700$5.64Jun 4, 2035$1.4M
17,901$31.98Jun 9, 2036$100K

Estimate: options held × ($37.54 − strike price), using the most recent insider trade price on Form 4 (Aug 27, 2026), not a market close.

Peter Harwin
!
Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Peter Harwin are complete.
Director
n/a0n/an/a
Vesting, gifts, unvested awards and holding lines for Peter Harwin

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Peter Harwin are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options heldStrike priceExpiresIntrinsic value (estimate)
44,700$8.92Jun 5, 2034$1.3M
44,700$5.64Jun 4, 2035$1.4M
17,901$31.98Jun 9, 2036$100K

Estimate: options held × ($37.54 − strike price), using the most recent insider trade price on Form 4 (Aug 27, 2026), not a market close.

Andrew Robbins
!
Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Andrew Robbins are complete.
President and CEO, Director
n/a0n/an/a
Vesting, gifts, unvested awards and holding lines for Andrew Robbins

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Andrew Robbins are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)
−367Kwithheld by the company for taxes

Stock options (not counted as shares):

Options heldStrike priceExpiresIntrinsic value (estimate)
1,100,000$4.63Jan 23, 2034$36.2M
915,000$8.89Jan 23, 2035$26.2M
245,000$39.45Dec 17, 2035$0

Estimate: options held × ($37.54 − strike price), using the most recent insider trade price on Form 4 (Aug 27, 2026), not a market close.

Todd Shegog
!
Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Todd Shegog are complete.
Director
n/a0n/an/a
Vesting, gifts, unvested awards and holding lines for Todd Shegog

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Todd Shegog are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)

Stock options (not counted as shares):

Options heldStrike priceExpiresIntrinsic value (estimate)
44,700$8.92Jun 5, 2034$1.3M
44,700$5.64Jun 4, 2035$1.4M
17,901$31.98Jun 9, 2036$100K

Estimate: options held × ($37.54 − strike price), using the most recent insider trade price on Form 4 (Aug 27, 2026), not a market close.

John Robinson
!
Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for John Robinson are complete.
Chief Scientific Officer
n/a−90Kn/an/a
Vesting, gifts, unvested awards and holding lines for John Robinson

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for John Robinson are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)
−140Kwithheld by the company for taxes

Stock options (not counted as shares):

Options heldStrike priceExpiresIntrinsic value (estimate)
300,000$4.63Jan 23, 2034$9.9M
270,000$8.89Jan 23, 2035$7.7M
65,000$39.45Dec 17, 2035$0

Estimate: options held × ($37.54 − strike price), using the most recent insider trade price on Form 4 (Aug 27, 2026), not a market close.

Evan Kearns
!
Holdings and share of stake are being verified. Share-of-stake figures and holdings for this company are held back while they are verified. Sales and other transactions for Evan Kearns are complete.
Chief Legal Officer
n/a−65Kn/an/a
Vesting, gifts, unvested awards and holding lines for Evan Kearns

Holdings and share of stake are being verified. Sales, proceeds, plan and tax status and dates for Evan Kearns are complete; balances and unit counts will be added when the check is finished.

0gifted (net of own trusts)
−126Kwithheld by the company for taxes

Stock options (not counted as shares):

Options heldStrike priceExpiresIntrinsic value (estimate)
255,000$4.63Jan 23, 2034$8.4M
230,000$8.89Jan 23, 2035$6.6M
55,000$39.45Dec 17, 2035$0

Estimate: options held × ($37.54 − strike price), using the most recent insider trade price on Form 4 (Aug 27, 2026), not a market close.

Holdings and share of stake for Cogent Biosciences, Inc. are being verified, so no balances, unit counts or percentages are shown. Sales, proceeds, plan and tax status, titles and dates come straight from individual filings.

What explains the selling$13.9M of sales by plan status, purpose, seller and month

Officer and director open-market sales: $13.9M across 360,152 shares. Plan status and stated purpose are separate questions, and a sale can have both.

By plan status

The lighter segment is sales with no plan disclosed in the filing ($12.2M), including tax-related sales outside a plan.

No plan disclosed · $12.2M

Sales with no 10b5-1 plan and no tax reference in the filing. $3.5M of it is John Robinson. No plan disclosed is a statement about the filing, not about why the sale happened. Largest such sale: John Robinson, Dec 26, 2025

Taxes

1,027,620 shares ($40.5M) were withheld by the company for taxes, which isn't a market sale.

SellerShares soldProceedsUnder a disclosed planShare of totalSales dates
John Robinson
Chief Scientific Officer
90K$3.5M0%25%Dec 26, 2025 to Dec 26, 2025
Jessica Sachs
Chief Medical Officer
83K$3.2M0%23%Dec 26, 2025 to Dec 26, 2025
John Green
Chief Financial Officer
77K$3.0M0%21%Dec 26, 2025 to Dec 26, 2025
Evan Kearns
Chief Legal Officer
65K$2.5M0%18%Dec 26, 2025 to Dec 26, 2025
Arlene Morris
Director
46K$1.7M100%12%Aug 27, 2026 to Aug 27, 2026

Sales by month

MonthSale proceedsDisclosed planTo cover taxesNo plan disclosed
Oct 2025$0$0$0$0
Nov 2025$0$0$0$0
Dec 2025$12.2M$0$0$12.2M
Jan 2026$0$0$0$0
Feb 2026$0$0$0$0
Mar 2026$0$0$0$0
Apr 2026$0$0$0$0
May 2026$0$0$0$0
Jun 2026$0$0$0$0
Jul 2026$0$0$0$0
Aug 2026$1.7M$1.7M$0$0
Sep 2026$0$0$0$0
Oct 2026$0$0$0$0
Is this normal? Selling year by year5 earlier years to compare with

More than usual: $13.9M sold, after almost none in the past 5 years. 5 insiders sold; the average is 0 a year.

12 months endingShares soldInsiders who soldProceeds
Oct 13, 2026
Latest 12 months
360K5$13.9M
Oct 13, 2025
1 year earlier
00$0
Oct 13, 2024
2 years earlier
00$0
Oct 14, 2023
3 years earlier
00$0
Oct 14, 2022
4 years earlier
00$0
Oct 14, 2021
5 years earlier
18K1$158K

Open-market sales (Form 4 code S) by people who were officers or directors, in split-adjusted shares. Earlier years include people who have since left. A sale that an outside holder also reports (a family trust, a fund) is counted with outside holders in every year. Shares, not dollars, are compared, so a change in the stock price doesn't look like a change in selling. Years the filings don't fully cover are shown but left out of the average.

Known gaps and uncertainty12 officers and directors not confirmed

Holdings and share of stake are being verified. Balances, unit counts and every share-of-stake figure for Cogent Biosciences, Inc. are held back until that check is finished. Sales, proceeds, plan and tax status, titles and dates come straight from individual filings and are complete.

External context: we only cite outside events when a documented connection exists. None is shown for this period.

Sources and methodology248 filings on record, 24 filed in the 12-month period, and how we read them

All 248 Forms 3, 4 and 5 on record for Cogent Biosciences, Inc. (SEC CIK 1622229), filed from Mar 28, 2018 to Oct 5, 2026; 24 of them were filed in the 12 months this page covers, retrieved from SEC EDGAR on Oct 13, 2026. Prices are the ones reported in each filing, often weighted averages.

Holdings. Each holding line (a share class plus an owner, such as a trust or LLC) carries its last reported balance forward. Entities first reported during the period start at zero, so transfers between an insider's own trusts don't count as selling. Lines not reported for three years or more are listed separately and left out of totals.

Sales. A sale counts as under a 10b5-1 plan if its footnote cites one or the filing's Rule 10b5-1 box is checked, and as tax-related if its footnote cites tax obligations or sell-to-cover. Shares withheld by the company for taxes are listed separately. Sales with neither attribute are labeled "no plan disclosed".

Full methodology

Former or inactive filers (17)No filing in 18 months; last reported balances, not in any total
NameLast filedLast reported balance
Dario CampanaOct 8, 20208,190,228 shares, last reported balance as of May 12, 2020
Venrock Healthcare Capital Partners III, L.P.Aug 18, 20204,355,273 shares, last reported balance as of Aug 18, 2020
Jorn AldagJul 6, 2020No balance on record
Bruce BoothJul 6, 2020No balance on record
Bruce BoothJul 6, 20203,361,535 shares, last reported balance as of Apr 3, 2018
Geoffrey HodgeFeb 13, 2020No balance on record
Seth EttenbergFeb 13, 2020No balance on record
Matthew OsborneFeb 13, 2020No balance on record
Liam RatcliffeJun 18, 2019No balance on record
Robert PerezJun 18, 2019No balance on record
Liam RatcliffeJun 18, 20191,795,545 shares, last reported balance as of Apr 3, 2018
Charles WilsonApr 11, 20195,095,114 shares, last reported balance as of Mar 28, 2018
Michael VasconcellesApr 11, 2019No balance on record
FMR LLCApr 5, 20182,412,590 shares, last reported balance as of Apr 3, 2018
FIL LtdApr 5, 20181,138,274 shares, last reported balance as of Apr 3, 2018
Atlas Venture Fund IX, L.P.Apr 3, 20183,361,535 shares, last reported balance as of Apr 3, 2018
Christiana StamoulisMar 28, 2018No balance on record

Spotted something wrong on this page? Report an error. We check every report against the SEC filing and list what we fix in the corrections log.