IDEAYA Biosciences (IDYA) SVP adds shares and gets 80,000 options

Rhea-AI Filing Summary

IDEAYA Biosciences officer Andres Ruiz Briseno reported new equity awards and share acquisitions. He acquired 682 common shares on 11/29/2024 at $23.256 and 1,253 shares on 11/28/2025 at $16.9065 under the company’s Employee Stock Purchase Plan, bringing his direct holdings to 26,466 shares.

He was also granted a stock option for 80,000 shares of common stock at an exercise price of $32.19 on 01/30/2026. According to the grant terms, 25% of the option vests on the first anniversary of January 1, 2026, with the remaining shares vesting in equal monthly installments over the following three years.

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

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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^*

Ruiz Briseno Andres

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
01/30/2026

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	11/29/2024		A(1)	V	682	A	$23.256	25,213	D
Common Stock	11/28/2025		A(1)	V	1,253	A	$16.9065	26,466	D

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
Stock Option (right to buy)	$32.19	01/30/2026		A		80,000		(2)	01/30/2036	Common Stock	80,000	$0	80,000	D

Explanation of Responses:

1. The shares were acquired under the Issuer's Employee Stock Purchase Plan in a transaction that was exempt under both Rule 16b-3(d) and Rule 16b-3(c).

2. 25% of the shares subject to the option vest on the first anniversary measured from January 1, 2026 (the "Vesting Commencement Date"), and 1/48th of the total number of shares vest monthly thereafter, such that 100% of the shares subject to the option will be fully vested and exercisable on the fourth anniversary of the Vesting Commencement Date.

Remarks:

Title: SVP, Head of Finance and Investor Relations

	/s/ Joshua Bleharski, as Attorney-in-Fact for Andres Ruiz Briseno	02/02/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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FAQ

What insider transactions did Andres Ruiz Briseno report for IDEAYA Biosciences (IDYA)?

Andres Ruiz Briseno reported ESPP share purchases and a stock option grant. He acquired 682 shares on 11/29/2024 and 1,253 shares on 11/28/2025, and received an option for 80,000 IDEAYA common shares on 01/30/2026.

How many IDEAYA Biosciences (IDYA) shares does Andres Ruiz Briseno own after these transactions?

After the reported Employee Stock Purchase Plan acquisitions, Andres Ruiz Briseno directly owns 26,466 shares of IDEAYA common stock. This figure reflects his holdings following the 1,253-share purchase reported for 11/28/2025 at a price of $16.9065 per share.

What are the key terms of Andres Ruiz Briseno’s 80,000 IDEAYA stock option grant?

The grant is a stock option for 80,000 IDEAYA common shares with an exercise price of $32.19 per share. It was awarded on 01/30/2026, with 25% vesting on the first anniversary of January 1, 2026 and the remainder vesting monthly thereafter.

How were the IDEAYA (IDYA) shares acquired by Andres Ruiz Briseno under the ESPP?

The filing states the shares were acquired under IDEAYA’s Employee Stock Purchase Plan in transactions exempt under Rule 16b-3(d) and Rule 16b-3(c). Purchases included 682 shares at $23.256 on 11/29/2024 and 1,253 shares at $16.9065 on 11/28/2025.

When do the IDEAYA stock options held by Andres Ruiz Briseno fully vest?

The option vests over four years from a Vesting Commencement Date of January 1, 2026. Twenty-five percent vests on the first anniversary of that date, and 1/48th of the total shares vests monthly thereafter until all 80,000 shares are fully vested and exercisable.

What position does Andres Ruiz Briseno hold at IDEAYA Biosciences (IDYA)?

The filing lists Andres Ruiz Briseno as an officer of IDEAYA Biosciences. In the remarks section, his title is given as SVP, Head of Finance and Investor Relations, indicating a senior finance and investor relations leadership role at the company.