Director Jeffrey Stein buys 50,000 IDEAYA Biosciences (IDYA) shares in market

Rhea-AI Filing Summary

IDEAYA Biosciences director Jeffrey Stein bought more company stock in the open market. On March 2, 2026, he purchased 50,000 shares of common stock in open-market transactions at a weighted average price of $32.9578 per share, with individual trades executed between $32.743 and $33.1999.

Following this purchase, he directly owns 54,281 common shares. An additional 3,363 shares are reported as held indirectly by his son.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Stein Jeffrey

(Last) (First) (Middle)

C/O IDEAYA BIOSCIENCES, INC.

5000 SHORELINE COURT, SUITE 300

(Street)

SOUTH SAN FRANCISCO CA 94080

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
IDEAYA Biosciences, Inc. [ IDYA ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
03/02/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/02/2026		P		50,000	A	$32.9578(1)	54,281	D
Common Stock								3,363	I	By Son
Common Stock								3,363	I	By Son

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. This transaction was executed in multiple trades in prices ranging from $32.743 to $33.1999, inclusive. The price reported in Column 4 above reflects the weighted average purchase price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares purchased at each respective price within the range set forth in this footnote.

	/s/ Douglas Snyder, as Attorney-in-Fact for Jeffrey Stein	03/02/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did IDEAYA Biosciences (IDYA) report for Jeffrey Stein?

IDEAYA Biosciences reported that director Jeffrey Stein bought 50,000 shares of common stock. The open-market purchase occurred on March 2, 2026, and was executed across multiple trades within a disclosed price range.

How many IDEAYA Biosciences (IDYA) shares did Jeffrey Stein buy and at what price?

Jeffrey Stein bought 50,000 IDEAYA Biosciences common shares at a weighted average price of $32.9578. The trades were executed in multiple lots, with individual prices ranging from $32.743 to $33.1999 per share.

What is Jeffrey Stein’s IDEAYA Biosciences (IDYA) share ownership after this Form 4 filing?

After the reported transaction, Jeffrey Stein directly owns 54,281 IDEAYA Biosciences common shares. The filing also shows 3,363 additional shares held indirectly, reported as being owned by his son.

Was the IDEAYA Biosciences (IDYA) insider transaction an open-market purchase or another type?

The IDEAYA Biosciences insider transaction was an open-market purchase of common stock. The Form 4 classifies the code as a standard purchase, executed across multiple trades on March 2, 2026, within a narrow price range.

Does the IDEAYA Biosciences (IDYA) Form 4 show any insider stock sales by Jeffrey Stein?

No insider stock sales by Jeffrey Stein are shown in this Form 4. The filing reports only a net purchase of 50,000 IDEAYA Biosciences common shares, increasing his directly held position.