IDEAYA Biosciences, Inc. — Director's Dealing 2021

Jan 28, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: IDEAYA Biosciences, Inc. (IDYA)
CIK: 0001676725
Period of Report: 2021-01-26

Reporting Person: Lackner Mark (SVP, Head of Biology)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-01-26	Common Stock	M	377	$4.62	Acquired	1378	Direct
2021-01-26	Common Stock	M	1123	$6.98	Acquired	2501	Direct
2021-01-26	Common Stock	S	1701	$18.2977	Disposed	800	Direct
2021-01-26	Common Stock	S	800	$18.7919	Disposed	0	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2021-01-26	Stock Option (right to buy)	$4.62	M	377	Disposed	2028-06-20	Common Stock (377)	Direct
2021-01-26	Stock Option (right to buy)	$6.98	M	1123	Disposed	2028-12-11	Common Stock (1123)	Direct

Footnotes

F1: Includes 1,001 shares acquired pursuant to Issuer's Employee Stock Purchase Plan on November 30, 2020.

F2: The transactions reported herein were effected pursuant to the Reporting Person's Rule 10b5-1 trading plan.

F3: This transaction was executed in multiple trades in prices ranging from $17.68 to $18.62, inclusive. The price reported in Column 4 above reflects the weighted average sale 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 sold at each respective price within the range set forth in this footnote.

F4: This transaction was executed in multiple trades in prices ranging from $18.68 to $18.895, inclusive. The price reported in Column 4 above reflects the weighted average sale 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 sold at each respective price within the range set forth in this footnote.

F5: 25% of the shares subject to the option vest on the first anniversary measured from May 31, 2018 (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.

F6: 25% of the shares subject to the option vest on the first anniversary measured from December 11, 2018 (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.