KYMR (NASDAQ: KYMR) Atlas Venture and Booth disclose multiple stock disposals

Rhea-AI Filing Summary

KYMR insiders and affiliated holders submitted a Form 144 notice for proposed resales of Common Stock by selling holders, including multiple transactions by Atlas Venture funds and an individual, Bruce Booth. The excerpt lists specific sale dates, share counts, and gross proceeds for transactions in April–June 2026.

The filings show examples such as Atlas Venture Fund X, L.P. selling 243,976 shares on 06/22/2026 for $24,182,608.35 and Atlas Venture Opportunity Fund I, L.P. selling 34,152 shares on 06/22/2026 for $3,385,105.26. Multiple smaller and larger dispositions by the same holders appear across 04/15/2026 through 06/23/2026.

Insights

Securities Attorney

Form 144 lists proposed resale transactions by affiliates with specific dates and amounts.

The notice catalogues proposed sales of Common Stock by affiliated holders, including Atlas Venture funds and an individual, with sale dates from 04/15/2026 through 06/23/2026. The entries give share counts and gross proceeds per trade.

Transaction timing and final execution depend on market activity and applicable resale exemptions; subsequent filings (e.g., Form 4 or broker reports) would confirm completed sales.

Equity Capital Markets Analyst

Multiple affiliated holders disclosed staged dispositions across April–June 2026, ranging from small lots to six-figure share sales.

The excerpt shows both modest trades (e.g., 88 shares on 04/22/2026) and large blocks (e.g., 243,976 shares on 06/22/2026), with gross dollar amounts listed alongside each trade.

These notices signal potential secondary supply; actual market impact depends on whether listed trades were executed and the timing of settlements.

Key Figures

Example sale by Atlas Venture Fund X: 243,976 shares Gross proceeds for 243,976-share entry: $24,182,608.35 Example sale by Atlas Venture Opportunity Fund I: 34,152 shares +4 more

7 metrics

Example sale by Atlas Venture Fund X 243,976 shares sale date <date>06/22/2026</date>

Gross proceeds for 243,976-share entry $24,182,608.35 Atlas Venture Fund X sale on <date>06/22/2026</date>

Example sale by Atlas Venture Opportunity Fund I 34,152 shares sale date <date>06/22/2026</date>

Gross proceeds for 34,152-share entry $3,385,105.26 Atlas Venture Opportunity Fund I sale on <date>06/22/2026</date>

Bruce Booth example sale 11,741 shares sale date <date>06/17/2026</date>

Gross proceeds for 11,741-share entry $1,056,443.24 Bruce Booth sale on <date>06/17/2026</date>

Small example trade 88 shares Atlas Venture Fund X sale on <date>04/22/2026</date>

Key Terms

Form 144, Private Placement, Common Stock, Issuer

4 terms

Form 144 regulatory

"Filer Information | 144: Filer Information"

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 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.

Common Stock financial

"144: Securities To Be Sold Common Stock"

Common stock represents ownership shares in a company, giving investors a stake in its success and a say in important decisions through voting rights. It is the most common type of stock traded on markets and can provide income through dividends, as well as potential for value growth. For investors, holding common stock means sharing in the company’s profits and risks.

Issuer regulatory

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

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Available on EDGAR 06/24/2026 - 05:29 PM Accepted by SEC EDGAR 06/24/2026 - 05:29 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	16542	1625251.5	82257588	06/24/2026	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			16542	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 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
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)

FAQ

What does KYMR's Form 144 filing show?

It lists proposed resales of KYMR Common Stock by affiliated holders during April–June 2026, with per-trade share counts and gross proceeds such as $24,182,608.35 for one 243,976-share entry on 06/22/2026.

Who are the main selling holders named in the KYMR excerpt?

The excerpt names Atlas Venture Fund X, L.P., Atlas Venture Opportunity Fund I, L.P., and individual Bruce Booth as selling holders, each with multiple dated entries showing shares and dollar amounts.

Do these Form 144 entries confirm the sales were completed?

No. Form 144 is a notice of proposed resale; the excerpt provides sale dates and amounts but does not by itself confirm settlement or final execution of the listed transactions.

What time period do the disclosed KYMR transactions cover?

The listed transactions in the excerpt span 04/14/2026 through 06/23/2026, with specific trade rows tied to those dates and per-trade proceeds shown.