KYMR (Nasdaq) affiliates and Bruce Booth report multiple share sales on Form 144

Rhea-AI Filing Summary

KYMR affiliate sales reported under Rule 144. The excerpt lists multiple sales of Common Stock by affiliated holders and individuals, including transactions on 04/15/2026, 04/22/2026, and 06/18/2026. Reported sellers include Atlas Venture Fund X, L.P., Atlas Venture Opportunity Fund I, L.P., and Bruce Booth. Sales are shown with share counts and gross proceeds per line.

Insights

Securities Compliance Analyst

Form 144 disclosures list insider-affiliate dispositions across three dates.

The filing records multiple sales of Common Stock by affiliated funds and an individual on 04/15/2026, 04/22/2026, and 06/18/2026

These notices are routine compliance disclosures under Rule 144; timing, method, and purchaser types are not detailed in the excerpt. Subsequent filings may disclose additional transaction mechanics or confirmations of sale.

Key Figures

Atlas Venture Fund X sale (06/18/2026): 92,169 shares Atlas Venture Fund X proceeds (06/18/2026): $8,330,667.41 Atlas Venture Opportunity Fund I sale (06/18/2026): 12,902 shares +3 more

6 metrics

Atlas Venture Fund X sale (06/18/2026) 92,169 shares sale dated 06/18/2026

Atlas Venture Fund X proceeds (06/18/2026) $8,330,667.41 gross proceeds shown for 92,169 shares on 06/18/2026

Atlas Venture Opportunity Fund I sale (06/18/2026) 12,902 shares sale dated 06/18/2026

Atlas Venture Opportunity Fund I proceeds (06/18/2026) $1,166,143.40 gross proceeds shown for 12,902 shares on 06/18/2026

Bruce Booth sale (06/18/2026) 11,741 shares sale dated 06/18/2026

Bruce Booth proceeds (06/18/2026) $1,056,443.24 gross proceeds shown for 11,741 shares on 06/18/2026

Key Terms

Form 144, Private Placement, Gross proceeds

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

"Common Stock | 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.

Gross proceeds financial

"Atlas Venture Fund X, L.P. ... 92,169 | 8330667.41"

The total amount of cash a company receives from a financing event or sale before any fees, expenses, taxes or deductions are taken out. Investors watch gross proceeds because it shows the raw scale of new capital being raised—think of it as the paycheck amount before withholdings—which helps assess how much funding is available for operations, growth, debt payoff or how much shareholder dilution might occur once costs are removed.

FAQ

What does KYMR Form 144 report?

The filing reports affiliated holders' proposed or completed sales of Common Stock. It lists sellers, dates, share counts, and gross proceeds for each transaction line.

Who are the primary sellers listed on the KYMR excerpt?

Sellers named include Atlas Venture Fund X, L.P., Atlas Venture Opportunity Fund I, L.P., and Bruce Booth, with multiple sale lines on specific dates in 2026.

Which sale dates appear in the KYMR Form 144 excerpt?

The excerpt shows transactions dated 04/14/2026, 04/15/2026, 04/22/2026, and 06/18/2026 as reported sale dates.

Are transaction amounts shown in the Form 144 excerpt?

Yes. Each line shows the number of shares and a dollar figure for gross proceeds, for example 92,169 shares with $8,330,667.41 on 06/18/2026.

Does this Form 144 indicate who received the sale proceeds?

The excerpt labels some entries as Issuer or Private Placement context, but it does not state which party received cash; cash‑flow treatment is not detailed in the provided lines.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 06/18/2026 - 05:36 PM Accepted by SEC EDGAR 06/18/2026 - 05:35 PM Learn about SEC filing dates

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	100928	9073427.2	82257588	06/18/2026	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			100928	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	06/18/2026	92169	8330667.41
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	06/18/2026	12902	1166143.4
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	06/18/2026	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)