KYMR (NASDAQ: KYMR) Atlas Venture, Bruce Booth report proposed share sales

Rhea-AI Filing Summary

KYMR affiliates reported proposed sales of Common Stock on Form 144. The notice lists multiple dispositions by Atlas Venture entities and by Bruce Booth on 04/15/2026, 04/22/2026, and 06/18/2026

Examples include Atlas Venture Fund X, L.P. proposing a sale of 92,169 shares on 06/18/2026 for $8,330,667.41, and Bruce Booth reporting 11,741 shares on 06/18/2026 for $1,056,443.24. The transactions are reported as resale of previously acquired common stock from a private placement.

Insights

Securities Counsel

Form 144s show proposed affiliate resales; filings are regulatory notices, not executed trades.

These Form 144 entries list proposed dispositions by affiliated holders, including Atlas Venture entities and Bruce Booth, with specific share counts and gross proceeds recorded on 04/15/2026, 04/22/2026, and 06/18/2026. Form 144 is a required notice for certain affiliate sales under resale rules.

Whether shares actually trade depends on market execution and any applicable transfer restrictions; subsequent filings or broker reports will show completion.

Capital Markets Analyst

Notable single-day filings show larger dispositions on 06/18/2026, which may temporarily increase sell-side activity.

The excerpt lists several larger sale notices on 06/18/2026, including Atlas Venture Fund X's 92,169 shares and Atlas Venture Opportunity Fund I's 12,902 shares. These are presented as resale amounts with associated gross proceeds.

Execution, timing, and market impact depend on whether the holders use brokered transactions and any resale limitations disclosed elsewhere; follow-up market data and subsequent Form 4/144 amendments will clarify outcomes.

Key Figures

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

6 metrics

Atlas Venture Fund X sale (example) 92,169 shares <date>06/18/2026</date>

Atlas Venture Fund X proceeds (example) $8,330,667.41 <date>06/18/2026</date>

Atlas Venture Opportunity Fund I sale (example) 12,902 shares <date>06/18/2026</date>

Atlas Venture Opportunity Fund I proceeds $1,166,143.40 <date>06/18/2026</date>

Bruce Booth sale (example) 11,741 shares <date>06/18/2026</date>

Bruce Booth proceeds (example) $1,056,443.24 <date>06/18/2026</date>

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 financial

"Common Stock | 03/11/2020 | Private Placement"

A private placement is a way for companies to raise money by selling securities directly to a small group of investors instead of through a public offering. This process is often quicker and less regulated, making it similar to offering a special, exclusive investment opportunity to select individuals or institutions. For investors, it can provide access to unique investment options that are not available on public markets.

Issuer regulatory

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

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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	14128	1270107.2	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			14128	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)

FAQ

What does KYMR's Form 144 filing show?

The filing lists proposed resales of Common Stock by affiliates. It records specific share counts and gross proceeds for dates including 06/18/2026 and 04/15/2026

Who are the primary sellers listed in the KYMR excerpt?

The excerpt lists Atlas Venture Fund X, L.P., Atlas Venture Opportunity Fund I, L.P., and Bruce Booth as sellers, each showing multiple proposed dispositions on April and June 2026 with share counts and proceeds.

Do Form 144 notices mean the shares were sold?

No. Form 144 is a required notice for proposed resale by affiliates. It records intended dispositions and amounts; actual sale execution and settlement are not confirmed by this notice alone.

What were the largest single dispositions shown in the excerpt?

Examples include 92,169 shares by Atlas Venture Fund X on 06/18/2026 for $8,330,667.41, and 12,902 shares by Atlas Venture Opportunity Fund I on 06/18/2026 for $1,166,143.40.

Where were proceeds and transaction dates reported?

Each row pairs a transaction date with gross proceeds. The excerpt shows proceeds in dollar amounts next to share counts for dates including 04/15/2026, 04/22/2026, and 06/18/2026.