DAWN

insider transactions

Day One Biopharmaceuticals, Inc. — buys & sells by directors, officers and 10% owners (SEC Form 4).

30D 90D 1Y

Net shares · 365d

-36.5K

0 buy · 36.5K sell

Net value · 365d

-$423.0K

$0 in · $423.0K out

Sentiment · 365d

Net selling

0% buying · 100% selling

Open-market trades · 365d

0 buy · 36.5K sell

Net buy / sell volume

Tap or hover the chart for daily net volume. Green = net buying, red = net selling.

All transactions

Other·D
Apr 23, 26

Lauren Merendino

Chief Commercial Officer

—

69.4K sh

Own -100%
Other·D
Apr 23, 26

Lauren Merendino

Chief Commercial Officer

—

40.6K sh

Own -100%
Other·D
Apr 23, 26

Lauren Merendino

Chief Commercial Officer

—

25.8K sh

Own -100%
Other·D
Apr 23, 26

Lauren Merendino

Chief Commercial Officer

—

19.0K sh

Own -100%
Other·D
Apr 23, 26

Lauren Merendino

Chief Commercial Officer

—

110.0K sh

Own -100%
Other·D
Apr 23, 26

Lauren Merendino

Chief Commercial Officer

—

90.0K sh

Own -100%
Other·D
Apr 23, 26

Lauren Merendino

Chief Commercial Officer

—

330.2K sh

Own -100%
Other·D
Apr 23, 26

Lauren Merendino

Chief Commercial Officer

—

60.2K sh

Own -100%
Other·D
Apr 23, 26

John A. Josey

Director

—

15.0K sh

Own -100%
Other·D
Apr 23, 26

John A. Josey

Director

—

22.5K sh

Own -100%
Other·D
Apr 23, 26

John A. Josey

Director

—

32.3K sh

Own -100%
Other·D
Apr 23, 26

John A. Josey

Director

—

37.5K sh

Own -100%
Other·D
Apr 23, 26

John A. Josey

Director

—

28.7K sh

Own -100%
Other·D
Apr 23, 26

John A. Josey

Director

—

1.2K sh

Own -100%
Other·D
Apr 23, 26

John A. Josey

Director

—

63.0K sh

Own -100%
Other·D
Apr 23, 26

John A. Josey

Director

—

72.3K sh

Own -100%
Other·D
Apr 23, 26

Adam Dubow

Gen Counsel & Secretary

—

65.6K sh

Own -100%
Other·D
Apr 23, 26

Adam Dubow

Gen Counsel & Secretary

—

40.6K sh

Own -100%
Other·D
Apr 23, 26

Adam Dubow

Gen Counsel & Secretary

—

25.8K sh

Own -100%
Other·D
Apr 23, 26

Adam Dubow

Gen Counsel & Secretary

—

5.2K sh

Own -100%
Other·D
Apr 23, 26

Adam Dubow

Gen Counsel & Secretary

—

8.9K sh

Own -100%
Other·D
Apr 23, 26

Adam Dubow

Gen Counsel & Secretary

—

105.0K sh

Own -100%
Other·D
Apr 23, 26

Adam Dubow

Gen Counsel & Secretary

—

90.0K sh

Own -100%
Other·D
Apr 23, 26

Adam Dubow

Gen Counsel & Secretary

—

309.0K sh

Own -100%
Other·D
Apr 23, 26

Adam Dubow

Gen Counsel & Secretary

—

72.7K sh

Own -100%
Other·D
Apr 23, 26

Michael Vasconcelles

Head of Research and Dev.

—

106.9K sh

Own -100%
Other·D
Apr 23, 26

Michael Vasconcelles

Head of Research and Dev.

—

226.0K sh

Own -100%
Other·D
Apr 23, 26

Michael Vasconcelles

Head of Research and Dev.

—

171.0K sh

Own -100%
Other·D
Apr 23, 26

Michael Vasconcelles

Head of Research and Dev.

—

346.0K sh

Own -100%
Other·D
Apr 23, 26

Michael Vasconcelles

Head of Research and Dev.

—

4.4K sh

Own -100%
Other·D
Apr 23, 26

William Grossman

Director

—

15.0K sh

Own -100%
Other·D
Apr 23, 26

William Grossman

Director

—

22.5K sh

Own -100%
Other·D
Apr 23, 26

William Grossman

Director

—

32.3K sh

Own -100%
Other·D
Apr 23, 26

William Grossman

Director

—

66.7K sh

Own -100%
Other·D
Apr 23, 26

Charles N York II KEY

COO and CFO

—

118.1K sh

Own -100%
Other·D
Apr 23, 26

Charles N York II KEY

COO and CFO

—

72.9K sh

Own -100%
Other·D
Apr 23, 26

Charles N York II KEY

COO and CFO

—

46.4K sh

Own -100%
Other·D
Apr 23, 26

Charles N York II KEY

COO and CFO

—

6.8K sh

Own -100%
Other·D
Apr 23, 26

Charles N York II KEY

COO and CFO

—

188.0K sh

Own -100%
Other·D
Apr 23, 26

Charles N York II KEY

COO and CFO

—

162.0K sh

Own -100%
Other·D
Apr 23, 26

Charles N York II KEY

COO and CFO

—

116.0K sh

Own -100%
Other·D
Apr 23, 26

Charles N York II KEY

COO and CFO

—

151.0K sh

Own -100%
Other·D
Apr 23, 26

Charles N York II KEY

COO and CFO

—

497.7K sh

Own -100%
Other·D
Apr 23, 26

Charles N York II KEY

COO and CFO

—

312.0K sh

Own -100%
Other·D
Apr 23, 26

Garry A Nicholson

Director

—

15.0K sh

Own -100%
Other·D
Apr 23, 26

Garry A Nicholson

Director

—

22.5K sh

Own -100%
Other·D
Apr 23, 26

Garry A Nicholson

Director

—

32.3K sh

Own -100%
Other·D
Apr 23, 26

Garry A Nicholson

Director

—

37.5K sh

Own -100%
Other·D
Apr 23, 26

Garry A Nicholson

Director

—

33.9K sh

Own -100%
Other·D
Apr 23, 26

Natalie C. Holles

Director

—

15.0K sh

Own -100%
Other·D
Apr 23, 26

Natalie C. Holles

Director

—

22.5K sh

Own -100%
Other·D
Apr 23, 26

Natalie C. Holles

Director

—

32.3K sh

Own -100%
Other·D
Apr 23, 26

Natalie C. Holles

Director

—

37.5K sh

Own -100%
Other·D
Apr 23, 26

Natalie C. Holles

Director

—

28.7K sh

Own -100%
Other·D
Apr 23, 26

Natalie C. Holles

Director

—

40.3K sh

Own -100%
Other·D
Apr 23, 26

Natalie C. Holles

Director

—

40.0K sh

Own -100%
Other·D
Apr 23, 26

Natalie C. Holles

Director

—

57.3K sh

Own -100%
Other·D
Apr 23, 26

Saira Ramasastry

Director

—

15.0K sh

Own -100%
Other·D
Apr 23, 26

Saira Ramasastry

Director

—

22.5K sh

Own -100%
Other·D
Apr 23, 26

Saira Ramasastry

Director

—

32.3K sh

Own -100%
Other·D
Apr 23, 26

Saira Ramasastry

Director

—

37.5K sh

Own -100%
Other·D
Apr 23, 26

Saira Ramasastry

Director

—

28.7K sh

Own -100%
Other·D
Apr 23, 26

Saira Ramasastry

Director

—

47.6K sh

Own -100%
Other·D
Apr 23, 26

Saira Ramasastry

Director

—

40.0K sh

Own -100%
Other·D
Apr 23, 26

Saira Ramasastry

Director

—

40.5K sh

Own -100%
Other·D
Apr 23, 26

Scott J. Garland

Director

—

15.0K sh

Own -100%
Other·D
Apr 23, 26

Scott J. Garland

Director

—

22.5K sh

Own -100%
Other·D
Apr 23, 26

Scott J. Garland

Director

—

32.3K sh

Own -100%
Other·D
Apr 23, 26

Scott J. Garland

Director

—

37.5K sh

Own -100%
Other·D
Apr 23, 26

Scott J. Garland

Director

—

28.7K sh

Own -100%
Other·D
Apr 23, 26

Scott J. Garland

Director

—

48.1K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

222.2K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

128.6K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

81.8K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

14.2K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

355.0K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

286.0K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

244.0K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

397.0K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

1.5M sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

808.3K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

18.2K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

147.7K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

300.0K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

20.2K sh

Own -100%
Other·D
Apr 23, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

204.6K sh

Own -100%
Grant·A
Feb 26, 26

Jeremy Bender

Director

—

117.5K sh

Own New
Grant·A
Feb 26, 26

Jeremy Bender

Director

$0

66.0K sh

Own New
Sell·S
Feb 17, 26

Lauren Merendino

Chief Commercial Officer

$67.4K

5.8K sh · $11.60

Own -9%
Sell·S
Feb 17, 26

Adam Dubow

Gen Counsel & Secretary

$74.2K

6.4K sh · $11.60

Own -8%
Sell·S
Feb 17, 26

Michael Vasconcelles

Head of Research and Dev.

$31.6K

2.7K sh · $11.60

Own -38%
Sell·S
Feb 17, 26

Charles N York II KEY

COO and CFO

$70.4K

6.1K sh · $11.60

Own -2%
Sell·S
Feb 17, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

$179.3K

15.5K sh · $11.60

Own -7%
Exercise·M
Feb 15, 26

Lauren Merendino

Chief Commercial Officer

$0

4.6K sh

Own +7%
Exercise·M
Feb 15, 26

Lauren Merendino

Chief Commercial Officer

$0

3.7K sh

Own +10%
Exercise·M
Feb 15, 26

Lauren Merendino

Chief Commercial Officer

$0

3.7K sh

Own +17%
Exercise·M
Feb 15, 26

Lauren Merendino

Chief Commercial Officer

$0

3.2K sh

Own +20%
Exercise·M
Feb 15, 26

Lauren Merendino

Chief Commercial Officer

—

4.6K sh

Own +8%
Exercise·M
Feb 15, 26

Lauren Merendino

Chief Commercial Officer

—

3.7K sh

Own +6%
Exercise·M
Feb 15, 26

Lauren Merendino

Chief Commercial Officer

—

3.7K sh

Own +7%
Exercise·M
Feb 15, 26

Lauren Merendino

Chief Commercial Officer

—

3.2K sh

Own +6%
Exercise·M
Feb 15, 26

Adam Dubow

Gen Counsel & Secretary

$0

4.4K sh

Own +7%
Exercise·M
Feb 15, 26

Adam Dubow

Gen Counsel & Secretary

$0

3.7K sh

Own +10%
Exercise·M
Feb 15, 26

Adam Dubow

Gen Counsel & Secretary

$0

3.7K sh

Own +17%
Exercise·M
Feb 15, 26

Adam Dubow

Gen Counsel & Secretary

$0

1.8K sh

Own +50%
Exercise·M
Feb 15, 26

Adam Dubow

Gen Counsel & Secretary

$0

3.0K sh

Own +50%
Exercise·M
Feb 15, 26

Adam Dubow

Gen Counsel & Secretary

—

4.4K sh

Own +6%
Exercise·M
Feb 15, 26

Adam Dubow

Gen Counsel & Secretary

—

3.7K sh

Own +5%
Exercise·M
Feb 15, 26

Adam Dubow

Gen Counsel & Secretary

—

3.7K sh

Own +5%
Exercise·M
Feb 15, 26

Adam Dubow

Gen Counsel & Secretary

—

1.8K sh

Own +3%
Exercise·M
Feb 15, 26

Adam Dubow

Gen Counsel & Secretary

—

3.0K sh

Own +5%
Exercise·M
Feb 15, 26

Michael Vasconcelles

Head of Research and Dev.

$0

7.1K sh

Own +7%
Exercise·M
Feb 15, 26

Michael Vasconcelles

Head of Research and Dev.

—

7.1K sh

Own New
Exercise·M
Feb 15, 26

Charles N York II KEY

COO and CFO

$0

7.9K sh

Own +7%
Exercise·M
Feb 15, 26

Charles N York II KEY

COO and CFO

$0

6.6K sh

Own +17%
Exercise·M
Feb 15, 26

Charles N York II KEY

COO and CFO

$0

2.2K sh

Own +50%
Exercise·M
Feb 15, 26

Charles N York II KEY

COO and CFO

—

7.9K sh

Own +3%
Exercise·M
Feb 15, 26

Charles N York II KEY

COO and CFO

—

6.6K sh

Own +2%
Exercise·M
Feb 15, 26

Charles N York II KEY

COO and CFO

—

2.2K sh

Own +1%
Exercise·M
Feb 15, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

$0

14.8K sh

Own +7%
Exercise·M
Feb 15, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

$0

11.7K sh

Own +10%
Exercise·M
Feb 15, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

$0

11.7K sh

Own +17%
Exercise·M
Feb 15, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

$0

4.8K sh

Own +50%
Exercise·M
Feb 15, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

14.8K sh

Own +7%
Exercise·M
Feb 15, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

11.7K sh

Own +6%
Exercise·M
Feb 15, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

11.7K sh

Own +6%
Exercise·M
Feb 15, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

—

4.8K sh

Own +3%
Grant·A
Jan 30, 26

Lauren Merendino

Chief Commercial Officer

$0

74.0K sh

Own New
Grant·A
Jan 30, 26

Lauren Merendino

Chief Commercial Officer

$0

110.0K sh

Own New
Grant·A
Jan 30, 26

Adam Dubow

Gen Counsel & Secretary

$0

70.0K sh

Own New
Grant·A
Jan 30, 26

Adam Dubow

Gen Counsel & Secretary

$0

105.0K sh

Own New
Grant·A
Jan 30, 26

Michael Vasconcelles

Head of Research and Dev.

$0

114.0K sh

Own New
Grant·A
Jan 30, 26

Michael Vasconcelles

Head of Research and Dev.

$0

171.0K sh

Own New
Grant·A
Jan 30, 26

Charles N York II KEY

COO and CFO

$0

126.0K sh

Own New
Grant·A
Jan 30, 26

Charles N York II KEY

COO and CFO

$0

188.0K sh

Own New
Grant·A
Jan 30, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

$0

237.0K sh

Own New
Grant·A
Jan 30, 26

Jeremy Bender KEY

CHIEF EXECUTIVE OFFICER

$0

355.0K sh

Own New

Date▾	Insider	Role	Type	Shares	Own Δ	Price	Value
Apr 23, 2026	Lauren Merendino	Chief Commercial Officer	Other D	69.4K	-100%	—	—
Apr 23, 2026	Lauren Merendino	Chief Commercial Officer	Other D	40.6K	-100%	—	—
Apr 23, 2026	Lauren Merendino	Chief Commercial Officer	Other D	25.8K	-100%	—	—
Apr 23, 2026	Lauren Merendino	Chief Commercial Officer	Other D	19.0K	-100%	—	—
Apr 23, 2026	Lauren Merendino	Chief Commercial Officer	Other D	110.0K	-100%	—	—
Apr 23, 2026	Lauren Merendino	Chief Commercial Officer	Other D	90.0K	-100%	—	—
Apr 23, 2026	Lauren Merendino	Chief Commercial Officer	Other D	330.2K	-100%	—	—
Apr 23, 2026	Lauren Merendino	Chief Commercial Officer	Other D	60.2K	-100%	—	—
Apr 23, 2026	John A. Josey	Director	Other D	15.0K	-100%	—	—
Apr 23, 2026	John A. Josey	Director	Other D	22.5K	-100%	—	—
Apr 23, 2026	John A. Josey	Director	Other D	32.3K	-100%	—	—
Apr 23, 2026	John A. Josey	Director	Other D	37.5K	-100%	—	—
Apr 23, 2026	John A. Josey	Director	Other D	28.7K	-100%	—	—
Apr 23, 2026	John A. Josey	Director	Other D	1.2K	-100%	—	—
Apr 23, 2026	John A. Josey	Director	Other D	63.0K	-100%	—	—
Apr 23, 2026	John A. Josey	Director	Other D	72.3K	-100%	—	—
Apr 23, 2026	Adam Dubow	Gen Counsel & Secretary	Other D	65.6K	-100%	—	—
Apr 23, 2026	Adam Dubow	Gen Counsel & Secretary	Other D	40.6K	-100%	—	—
Apr 23, 2026	Adam Dubow	Gen Counsel & Secretary	Other D	25.8K	-100%	—	—
Apr 23, 2026	Adam Dubow	Gen Counsel & Secretary	Other D	5.2K	-100%	—	—
Apr 23, 2026	Adam Dubow	Gen Counsel & Secretary	Other D	8.9K	-100%	—	—
Apr 23, 2026	Adam Dubow	Gen Counsel & Secretary	Other D	105.0K	-100%	—	—
Apr 23, 2026	Adam Dubow	Gen Counsel & Secretary	Other D	90.0K	-100%	—	—
Apr 23, 2026	Adam Dubow	Gen Counsel & Secretary	Other D	309.0K	-100%	—	—
Apr 23, 2026	Adam Dubow	Gen Counsel & Secretary	Other D	72.7K	-100%	—	—
Apr 23, 2026	Michael Vasconcelles	Head of Research and Dev.	Other D	106.9K	-100%	—	—
Apr 23, 2026	Michael Vasconcelles	Head of Research and Dev.	Other D	226.0K	-100%	—	—
Apr 23, 2026	Michael Vasconcelles	Head of Research and Dev.	Other D	171.0K	-100%	—	—
Apr 23, 2026	Michael Vasconcelles	Head of Research and Dev.	Other D	346.0K	-100%	—	—
Apr 23, 2026	Michael Vasconcelles	Head of Research and Dev.	Other D	4.4K	-100%	—	—
Apr 23, 2026	William Grossman	Director	Other D	15.0K	-100%	—	—
Apr 23, 2026	William Grossman	Director	Other D	22.5K	-100%	—	—
Apr 23, 2026	William Grossman	Director	Other D	32.3K	-100%	—	—
Apr 23, 2026	William Grossman	Director	Other D	66.7K	-100%	—	—
Apr 23, 2026	Charles N York II KEY	COO and CFO	Other D	118.1K	-100%	—	—
Apr 23, 2026	Charles N York II KEY	COO and CFO	Other D	72.9K	-100%	—	—
Apr 23, 2026	Charles N York II KEY	COO and CFO	Other D	46.4K	-100%	—	—
Apr 23, 2026	Charles N York II KEY	COO and CFO	Other D	6.8K	-100%	—	—
Apr 23, 2026	Charles N York II KEY	COO and CFO	Other D	188.0K	-100%	—	—
Apr 23, 2026	Charles N York II KEY	COO and CFO	Other D	162.0K	-100%	—	—
Apr 23, 2026	Charles N York II KEY	COO and CFO	Other D	116.0K	-100%	—	—
Apr 23, 2026	Charles N York II KEY	COO and CFO	Other D	151.0K	-100%	—	—
Apr 23, 2026	Charles N York II KEY	COO and CFO	Other D	497.7K	-100%	—	—
Apr 23, 2026	Charles N York II KEY	COO and CFO	Other D	312.0K	-100%	—	—
Apr 23, 2026	Garry A Nicholson	Director	Other D	15.0K	-100%	—	—
Apr 23, 2026	Garry A Nicholson	Director	Other D	22.5K	-100%	—	—
Apr 23, 2026	Garry A Nicholson	Director	Other D	32.3K	-100%	—	—
Apr 23, 2026	Garry A Nicholson	Director	Other D	37.5K	-100%	—	—
Apr 23, 2026	Garry A Nicholson	Director	Other D	33.9K	-100%	—	—
Apr 23, 2026	Natalie C. Holles	Director	Other D	15.0K	-100%	—	—
Apr 23, 2026	Natalie C. Holles	Director	Other D	22.5K	-100%	—	—
Apr 23, 2026	Natalie C. Holles	Director	Other D	32.3K	-100%	—	—
Apr 23, 2026	Natalie C. Holles	Director	Other D	37.5K	-100%	—	—
Apr 23, 2026	Natalie C. Holles	Director	Other D	28.7K	-100%	—	—
Apr 23, 2026	Natalie C. Holles	Director	Other D	40.3K	-100%	—	—
Apr 23, 2026	Natalie C. Holles	Director	Other D	40.0K	-100%	—	—
Apr 23, 2026	Natalie C. Holles	Director	Other D	57.3K	-100%	—	—
Apr 23, 2026	Saira Ramasastry	Director	Other D	15.0K	-100%	—	—
Apr 23, 2026	Saira Ramasastry	Director	Other D	22.5K	-100%	—	—
Apr 23, 2026	Saira Ramasastry	Director	Other D	32.3K	-100%	—	—
Apr 23, 2026	Saira Ramasastry	Director	Other D	37.5K	-100%	—	—
Apr 23, 2026	Saira Ramasastry	Director	Other D	28.7K	-100%	—	—
Apr 23, 2026	Saira Ramasastry	Director	Other D	47.6K	-100%	—	—
Apr 23, 2026	Saira Ramasastry	Director	Other D	40.0K	-100%	—	—
Apr 23, 2026	Saira Ramasastry	Director	Other D	40.5K	-100%	—	—
Apr 23, 2026	Scott J. Garland	Director	Other D	15.0K	-100%	—	—
Apr 23, 2026	Scott J. Garland	Director	Other D	22.5K	-100%	—	—
Apr 23, 2026	Scott J. Garland	Director	Other D	32.3K	-100%	—	—
Apr 23, 2026	Scott J. Garland	Director	Other D	37.5K	-100%	—	—
Apr 23, 2026	Scott J. Garland	Director	Other D	28.7K	-100%	—	—
Apr 23, 2026	Scott J. Garland	Director	Other D	48.1K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	222.2K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	128.6K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	81.8K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	14.2K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	355.0K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	286.0K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	244.0K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	397.0K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	1.5M	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	808.3K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	18.2K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	147.7K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	300.0K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	20.2K	-100%	—	—
Apr 23, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Other D	204.6K	-100%	—	—
Feb 26, 2026	Jeremy Bender	Director	Grant A	117.5K	New	—	—
Feb 26, 2026	Jeremy Bender	Director	Grant A	66.0K	New	—	$0
Feb 17, 2026	Lauren Merendino	Chief Commercial Officer	Sell S	5.8K	-9%	$11.60	$67.4K
Feb 17, 2026	Adam Dubow	Gen Counsel & Secretary	Sell S	6.4K	-8%	$11.60	$74.2K
Feb 17, 2026	Michael Vasconcelles	Head of Research and Dev.	Sell S	2.7K	-38%	$11.60	$31.6K
Feb 17, 2026	Charles N York II KEY	COO and CFO	Sell S	6.1K	-2%	$11.60	$70.4K
Feb 17, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Sell S	15.5K	-7%	$11.60	$179.3K
Feb 15, 2026	Lauren Merendino	Chief Commercial Officer	Exercise M	4.6K	+7%	—	$0
Feb 15, 2026	Lauren Merendino	Chief Commercial Officer	Exercise M	3.7K	+10%	—	$0
Feb 15, 2026	Lauren Merendino	Chief Commercial Officer	Exercise M	3.7K	+17%	—	$0
Feb 15, 2026	Lauren Merendino	Chief Commercial Officer	Exercise M	3.2K	+20%	—	$0
Feb 15, 2026	Lauren Merendino	Chief Commercial Officer	Exercise M	4.6K	+8%	—	—
Feb 15, 2026	Lauren Merendino	Chief Commercial Officer	Exercise M	3.7K	+6%	—	—
Feb 15, 2026	Lauren Merendino	Chief Commercial Officer	Exercise M	3.7K	+7%	—	—
Feb 15, 2026	Lauren Merendino	Chief Commercial Officer	Exercise M	3.2K	+6%	—	—
Feb 15, 2026	Adam Dubow	Gen Counsel & Secretary	Exercise M	4.4K	+7%	—	$0
Feb 15, 2026	Adam Dubow	Gen Counsel & Secretary	Exercise M	3.7K	+10%	—	$0
Feb 15, 2026	Adam Dubow	Gen Counsel & Secretary	Exercise M	3.7K	+17%	—	$0
Feb 15, 2026	Adam Dubow	Gen Counsel & Secretary	Exercise M	1.8K	+50%	—	$0
Feb 15, 2026	Adam Dubow	Gen Counsel & Secretary	Exercise M	3.0K	+50%	—	$0
Feb 15, 2026	Adam Dubow	Gen Counsel & Secretary	Exercise M	4.4K	+6%	—	—
Feb 15, 2026	Adam Dubow	Gen Counsel & Secretary	Exercise M	3.7K	+5%	—	—
Feb 15, 2026	Adam Dubow	Gen Counsel & Secretary	Exercise M	3.7K	+5%	—	—
Feb 15, 2026	Adam Dubow	Gen Counsel & Secretary	Exercise M	1.8K	+3%	—	—
Feb 15, 2026	Adam Dubow	Gen Counsel & Secretary	Exercise M	3.0K	+5%	—	—
Feb 15, 2026	Michael Vasconcelles	Head of Research and Dev.	Exercise M	7.1K	+7%	—	$0
Feb 15, 2026	Michael Vasconcelles	Head of Research and Dev.	Exercise M	7.1K	New	—	—
Feb 15, 2026	Charles N York II KEY	COO and CFO	Exercise M	7.9K	+7%	—	$0
Feb 15, 2026	Charles N York II KEY	COO and CFO	Exercise M	6.6K	+17%	—	$0
Feb 15, 2026	Charles N York II KEY	COO and CFO	Exercise M	2.2K	+50%	—	$0
Feb 15, 2026	Charles N York II KEY	COO and CFO	Exercise M	7.9K	+3%	—	—
Feb 15, 2026	Charles N York II KEY	COO and CFO	Exercise M	6.6K	+2%	—	—
Feb 15, 2026	Charles N York II KEY	COO and CFO	Exercise M	2.2K	+1%	—	—
Feb 15, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Exercise M	14.8K	+7%	—	$0
Feb 15, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Exercise M	11.7K	+10%	—	$0
Feb 15, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Exercise M	11.7K	+17%	—	$0
Feb 15, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Exercise M	4.8K	+50%	—	$0
Feb 15, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Exercise M	14.8K	+7%	—	—
Feb 15, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Exercise M	11.7K	+6%	—	—
Feb 15, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Exercise M	11.7K	+6%	—	—
Feb 15, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Exercise M	4.8K	+3%	—	—
Jan 30, 2026	Lauren Merendino	Chief Commercial Officer	Grant A	74.0K	New	—	$0
Jan 30, 2026	Lauren Merendino	Chief Commercial Officer	Grant A	110.0K	New	—	$0
Jan 30, 2026	Adam Dubow	Gen Counsel & Secretary	Grant A	70.0K	New	—	$0
Jan 30, 2026	Adam Dubow	Gen Counsel & Secretary	Grant A	105.0K	New	—	$0
Jan 30, 2026	Michael Vasconcelles	Head of Research and Dev.	Grant A	114.0K	New	—	$0
Jan 30, 2026	Michael Vasconcelles	Head of Research and Dev.	Grant A	171.0K	New	—	$0
Jan 30, 2026	Charles N York II KEY	COO and CFO	Grant A	126.0K	New	—	$0
Jan 30, 2026	Charles N York II KEY	COO and CFO	Grant A	188.0K	New	—	$0
Jan 30, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Grant A	237.0K	New	—	$0
Jan 30, 2026	Jeremy Bender KEY	CHIEF EXECUTIVE OFFICER	Grant A	355.0K	New	—	$0

About DAWN insider trading

This page tracks insider transactions for Day One Biopharmaceuticals, Inc. (DAWN) reported to the U.S. Securities and Exchange Commission on Form 4. Corporate insiders — directors, executive officers and beneficial owners of more than 10% of the stock — must disclose their trades within two business days. Open-market purchases (code P) and sales (code S) made at the insider's discretion are the most-watched opportunistic signals, while awards (A), option exercises (M) and tax-withholding (F) reflect compensation rather than conviction. Trades marked 10b5-1 were made under a pre-arranged plan and are considered routine. A cluster buy — several insiders buying within a short window — is historically a stronger bullish indicator than any single trade.