KYMR (NASDAQ: KYMR) insiders file Form 144 to sell shares

Rhea-AI Filing Summary

KYMR notice: Section 144 filings report proposed sales of Common Stock by several holders. Examples include Atlas Venture Fund X, L.P. proposing 71,814 shares on 03/02/2026 for $6,472,674.74 and other smaller dispositions in March–April 2026.

Key Figures

Atlas Venture Fund X proposed sale: 71,814 shares Atlas Venture Fund X gross amount: $6,472,674.74 Bruce Booth sales (examples): 4,159 and 2,200 shares +2 more

5 metrics

Atlas Venture Fund X proposed sale 71,814 shares proposed sale on <date>03/02/2026</date>

Atlas Venture Fund X gross amount $6,472,674.74 amount associated with 71,814 shares on <date>03/02/2026</date>

Bruce Booth sales (examples) 4,159 and 2,200 shares proposed sales on <date>04/14/2026</date> and <date>04/15/2026</date>

Atlas Venture Opportunity Fund I proposed sale 10,052 shares proposed sale on <date>03/02/2026</date>

Form type Form 144 notice of proposed sale under Section 144

Key Terms

Form 144, Private Placement, Gross amount

3 terms

Form 144 regulatory

"Common Stock | Merrill Lynch ... | 04/22/2026 | Nasdaq 144: Securities To Be Sold"

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 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.

Gross amount financial

"Atlas Venture Fund X, L.P. ... | 03/02/2026 | 71814 | 6472674.74"

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	88	7750.16	81642394	04/22/2026	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			88	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	03/02/2026	71814	6472674.74
Atlas Venture Fund X, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	04/15/2026	2750	247765.57
Atlas Venture Opportunity Fund I, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	03/02/2026	10052	905997.81
Atlas Venture Opportunity Fund I, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common	04/15/2026	385	34687.18
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

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 mean?

It notifies the SEC of proposed insider sales of KYMR common stock. The filing lists proposed dispositions by named holders, dates, share counts, and gross sale amounts for transactions in March and April 2026.

Who are the primary sellers listed in the KYMR Form 144?

Named sellers include Atlas Venture Fund X, Atlas Venture Opportunity Fund I, and Bruce Booth. The filing shows specific sale dates and per‑holder share counts and gross amounts for March–April 2026.

How many shares did Atlas Venture Fund X propose to sell in the filing?

Atlas Venture Fund X proposed 71,814 shares on 03/02/2026. The filing records a gross amount of $6,472,674.74 associated with that disposition.

Are these sales reported as completed in the KYMR Form 144?

Form 144 is a notice of proposed sales, not proof of completion. The filing lists intended sale dates and gross amounts; execution and final proceeds are not confirmed here.

Do the Form 144 entries show sales by company insiders or by the issuer?

The entries list named holders proposing to sell shares (insiders/holders), not sales by the issuer. The filing identifies sellers such as Atlas funds and Bruce Booth with dates and amounts.