YORK CHARLES N II

PrivateCIK: 1655962
Location

BRISBANE, CA

YORK CHARLES N II (COO, CFO and Secretary) reported 1 transaction at DAY ONE BIOPHARMACEUTICALS, INC.

Review the transaction codes below to understand the nature of each event.

InsiderYORK CHARLES N IICIK 1655962
Officer· COO, CFO and Secretary
Since May 2021
-1.83M
Net shares
Net seller
$0.00
Total acquired
0
Open market trades
0B · 0S
11
Total transactions
1.83M disposed
Non-Derivative Transactions1

Common Stock

Direct
D · Disposition

Shares

312.02K

Price / share

Trade value

% of position

New position
4/23/2026
312.02K0.00
Total

Net shares

312.02K

Net value

$0.00

Derivative Transactions10

Stock Option (right to buy Common Stock)

Direct
D · Disposition
Converts to

Common Stock

497.67K shares

Shares

497.67K

Strike price

8.99

Held after

0.00

Exercisable

4/23/2026

Stock Option (right to buy Common Stock)

Direct
D · Disposition
Converts to

Common Stock

151K shares

Shares

151K

Strike price

8.99

Held after

0.00

Exercisable

4/23/2026

Stock Option (right to buy Common Stock)

Direct
D · Disposition
Converts to

Common Stock

116K shares

Shares

116K

Strike price

8.99

Held after

0.00

Exercisable

4/23/2026

Stock Option (right to buy Common Stock)

Direct
D · Disposition
Converts to

Common Stock

162K shares

Shares

162K

Strike price

8.99

Held after

0.00

Exercisable

4/23/2026

Stock Option (right to buy Common Stock)

Direct
D · Disposition
Converts to

Common Stock

162K shares

Shares

162K

Strike price

8.99

Held after

0.00

Exercisable

4/23/2026

Stock Option (right to buy Common Stock)

Direct
D · Disposition
Converts to

Common Stock

188K shares

Shares

188K

Strike price

11.16

Held after

0.00

Exercisable

4/23/2026

Restricted Stock Unit (RSU)

Direct
D · Disposition
Converts to

Common Stock

6.75K shares

Shares

6.75K

Strike price

Held after

0.00

Exercisable

4/23/2026

Restricted Stock Unit (RSU)

Direct
D · Disposition
Converts to

Common Stock

46.38K shares

Shares

46.38K

Strike price

Held after

0.00

Exercisable

4/23/2026

Restricted Stock Unit (RSU)

Direct
D · Disposition
Converts to

Common Stock

72.88K shares

Shares

72.88K

Strike price

Held after

0.00

Exercisable

4/23/2026

Restricted Stock Unit (RSU)

Direct
D · Disposition
Converts to

Common Stock

118.13K shares

Shares

118.13K

Strike price

Held after

0.00

Exercisable

4/23/2026
YORK CHARLES N II — Insider Transaction (Form 4) Filed Apr 23, 2026 | Finecho