KYMR (KYMR) selling holders file Rule 144 notices including Atlas Venture

Rhea-AI Filing Summary

KYMR reported notices of proposed sale of Common Stock by multiple selling holders under Rule 144. The excerpt lists specific sale notices and recent transactions by holders such as Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P., and individual holders including Bruce Booth.

The filings show proposed or recent sales on dates including 04/15/2026, 04/22/2026, and multiple dates in June 2026, with per‑transaction share counts and dollar amounts reported for each selling holder.

Insights

Securities Counsel

Notices list multiple proposed sales by affiliated funds and an individual.

The excerpt is a series of Rule 144 sale notices for Common Stock, naming holders such as Atlas Venture Fund X, L.P., Atlas Venture Opportunity Fund I, L.P., and Bruce Booth. Each line records a sale date, number of shares, and the dollar proceeds for that transaction.

Cash‑flow treatment and any transfer restrictions are not stated in the excerpt; subsequent filings or broker confirmations would show closing details and whether sales were pursuant to registered or private sale conditions.

Key Figures

Example sale — Atlas Venture Fund X on 06/25/2026: 480,992 shares Proceeds — Atlas Venture Fund X on 06/25/2026: $57,122,898.52 Example sale — Atlas Venture Fund X on 06/26/2026: 410,427 shares +4 more

7 metrics

Example sale — Atlas Venture Fund X on 06/25/2026 480,992 shares sale dated 06/25/2026

Proceeds — Atlas Venture Fund X on 06/25/2026 $57,122,898.52 dollar amount reported for the 06/25/2026 sale

Example sale — Atlas Venture Fund X on 06/26/2026 410,427 shares sale dated 06/26/2026

Proceeds — Atlas Venture Fund X on 06/26/2026 $45,267,758.67 dollar amount reported for the 06/26/2026 sale

Example sale — Atlas Venture Opportunity Fund I on 06/25/2026 67,329 shares sale dated 06/25/2026

Example sale — Bruce Booth on 06/17/2026 11,741 shares sale dated 06/17/2026

Securities listed for sale (type) Common Stock identified security class in the excerpt

Key Terms

Form 144, Private Placement, Issuer

3 terms

Form 144 regulatory

"144: Securities Sold During The Past 3 Months"

Form 144 is a document that investors must file with the government when they plan to sell a large number of shares of a company's stock. It helps ensure transparency so everyone knows how many shares are being sold and when, which can impact the stock's price.

Private Placement market

"03/11/2020 | Private Placement | Issuer"

A private placement is a sale of securities directly to a selected group of investors, typically institutions or accredited investors, instead of through a public offering. It lets a company raise money faster and with fewer regulatory steps; for existing shareholders it matters because the newly issued shares, often sold at a discount, increase the share count and can dilute their ownership.

Issuer regulatory

"Private Placement | Issuer"

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Available on EDGAR 06/29/2026 - 05:52 PM Accepted by SEC EDGAR 06/29/2026 - 05:51 PM Learn about SEC filing dates

FAQ

What does KYMR's Form 144 filing mean for shareholders?

It notifies proposed sales of Common Stock by identified holders and reports recent transactions. The excerpt lists sale dates, share counts, and proceeds for holders including Atlas Venture funds and Bruce Booth, but it does not state whether the sales have settled.

Who are the largest selling holders listed in the KYMR excerpt?

Examples shown include Atlas Venture Fund X, L.P. and Atlas Venture Opportunity Fund I, L.P. The excerpt lists multiple transactions by these funds with specific share counts and dollar amounts on April and June 2026 dates.

Does the excerpt state how many total shares are being registered or sold?

The excerpt provides per‑transaction share counts and dollar proceeds but does not present a single aggregate registered amount. Information is shown by holder and date, not as an aggregate total in the provided text.

Are sale proceeds paid to the issuer according to the Form 144 excerpt?

The excerpt records dollar amounts for each transaction but does not state the cash‑flow recipient. It lists sales by holders and shows proceeds per transaction without specifying whether proceeds go to the issuer or selling holders.

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK
Filer CCC
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer

SEC File Number

Address of Issuer

Phone

Name of Person for Whose Account the Securities are To Be Sold

See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.

Relationship to Issuer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common Stock	Merrill Lynch 555 California Street 18th Floor San Francisco CA 94104	10473	1132340.76	82257588	06/29/2026	Nasdaq

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common Stock	03/11/2020	Private Placement	Issuer			10473	03/11/2020	Cash

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Atlas Venture Fund X, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	04/15/2026	2750	247765.57
Atlas Venture Fund X, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	04/22/2026	88	7926.6
Atlas Venture Fund X, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/17/2026	92169	8330667.41
Atlas Venture Fund X, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/18/2026	100928	9185730.49
Atlas Venture Fund X, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/22/2026	243976	24182608.35
Atlas Venture Fund X, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/23/2026	1235	123470.07
Atlas Venture Fund X, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/24/2026	118178	11877944.68
Atlas Venture Fund X, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/25/2026	480992	57122898.52
Atlas Venture Fund X, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/26/2026	410427	45267758.67
Atlas Venture Opportunity Fund I, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	04/15/2026	385	34687.18
Atlas Venture Opportunity Fund I, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	04/22/2026	12	1080.9
Atlas Venture Opportunity Fund I, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/17/2026	12902	1166143.4
Atlas Venture Opportunity Fund I, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/18/2026	14128	1285827.52
Atlas Venture Opportunity Fund I, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/22/2026	34152	3385105.26
Atlas Venture Opportunity Fund I, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/23/2026	173	17295.81
Atlas Venture Opportunity Fund I, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/24/2026	16542	1662618.77
Atlas Venture Opportunity Fund I, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/25/2026	67329	7996032.44
Atlas Venture Opportunity Fund I, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/26/2026	57451	6336517.83
Bruce Booth 300 Technology Sq Ste 8 Cambridge MA 02139	Common	04/14/2026	4159	374199.56
Bruce Booth 300 Technology Sq Ste 8 Cambridge MA 02139	Common	04/15/2026	2200	197895.00
Bruce Booth 300 Technology Sq Ste 8 Cambridge MA 02139	Common	04/22/2026	5900	530746.25
Bruce Booth 300 Technology Sq Ste 8 Cambridge MA 02139	Common	06/17/2026	11741	1056443.24

144: Remarks and Signature

Remarks

Date of Notice

Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1

ATTENTION:

The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.

Signature

ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)