[144] Day One Biopharmaceuticals, Inc. SEC Filing

Rhea-AI Filing Summary

Day One Biopharmaceuticals (DAWN) filed a Form 144 reporting a proposed sale of 16,058 common shares acquired as restricted stock from the issuer on 08/15/2025. The sale is to be effected through Morgan Stanley Smith Barney LLC on NASDAQ with an aggregate market value reported as $108,666.09 and the issuer's total shares outstanding listed as 102,431,933.

The notice records the approximate sale date as 08/18/2025, states no securities were sold by the reporting person in the past three months, and includes the standard representation that the seller is not aware of undisclosed material adverse information. Payment and acquisition details show the shares were issued and paid on 08/15/2025 and described as not applicable for other payment types.

Positive

• Form 144 filed with full required fields including broker, exchange, quantity, and acquisition details
• Includes seller attestation that there is no undisclosed material adverse information
• Specifies acquisition as restricted stock and lists both acquisition and intended sale dates

Negative

• None.

Insights

Securities Analyst

TL;DR Routine Rule 144 notice: small-block insider sale disclosed with broker, exchange, and acquisition details.

The filing formally notifies the market of a proposed sale of 16,058 common shares through Morgan Stanley Smith Barney LLC on NASDAQ

The document specifies the shares were restricted stock issued by the company on 08/15/2025 and lists the approximate sale date as 08/18/2025. It also confirms no sales by the person in the prior three months and includes the standard attestation about the absence of undisclosed material adverse information. For investors this is a compliance disclosure rather than a substantive corporate development.

Corporate Governance Expert

TL;DR Disclosure aligns with Rule 144 procedural requirements; contains key broker, acquisition, and signature representations.

The form provides required granular details: class of security, acquisition date and nature (restricted stock), broker name and address, aggregate market value, shares outstanding, and an approximate sale date. It reiterates the seller's legal attestation about material information and warns of criminal penalties for false statements. This filing demonstrates procedural governance compliance without indicating any governance event or control change.

08/18/2025 - 05:33 PM

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

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	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	16058	108666.09	102431933	08/18/2025	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	08/15/2025	RESTRICTED STOCK	ISSUER			16058	08/15/2025	Not Applicable

* 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

Nothing to Report

144: Remarks and Signature

Remarks

Date of Notice

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 DAWN's Form 144 report?

The form reports a proposed sale of 16,058 common shares acquired as restricted stock from the issuer on 08/15/2025.

Through which broker and exchange will DAWN shares be sold?

The sale is reported to be through Morgan Stanley Smith Barney LLC on NASDAQ.

What is the aggregate market value of the shares in the Form 144?

The aggregate market value is reported as $108,666.09 for the 16,058 shares.

When is the approximate date of sale listed in the filing?

The approximate date of sale is listed as 08/18/2025.

Does the filer report any other sales in the past three months?

The filing states Nothing to Report for securities sold during the past three months.