ATAY OGUZHAN (See Remarks) sold 21.7% of their position (45K shares) of BILLIONTOONE, INC. on the open market

Open‑market sale worth $6.17M — a significant reduction. Review remaining holdings and any 10b5‑1 plan disclosures.

S · 23 sales

ATAY OGUZHAN

Filed: 8/6/2026ACC: 0002070849-26-000052

InsiderATAY OGUZHANCIK 2088549

→

IssuerBILLIONTOONE, INC.CIK 2070849

DirectorOfficer· See Remarks

Since Nov 2025

-45K

Net shares

Net seller

$6.17M

Total sold

Open market trades

0B · 23S

Total transactions

32.50K acquired · 77.50K disposed

Non-Derivative Transactions26

Class A Common Stock

Direct

M · Option Exercise

+20K

Price / share

$2.80

Trade value

$56K

% of position

New position

8/3/2026

0.00→20K

Class A Common Stock

Direct

M · Option Exercise

+6.25K

Price / share

$2.80

Trade value

$17.50K

% of position

31.3%

8/3/2026

20K→26.25K

Class A Common Stock

Direct

M · Option Exercise

+6.25K

Price / share

$2.80

Trade value

$17.50K

% of position

23.8%

8/3/2026

26.25K→32.50K

Class A Common Stock

Direct

S · Sale

−269.00

Price / share

$133.01

Trade value

$35.78K

% of position

0.8%

8/3/2026

32.50K→32.23K

Class A Common Stock

Direct

S · Sale

−555.00

Price / share

$133.81

Trade value

$74.26K

% of position

1.7%

8/3/2026

32.23K→31.68K

Class A Common Stock

Direct

S · Sale

−135.00

Price / share

$135.42

Trade value

$18.28K

% of position

0.4%

8/3/2026

31.68K→31.54K

Class A Common Stock

Direct

S · Sale

−6.35K

Price / share

$136.42

Trade value

$866.84K

% of position

20.1%

8/3/2026

31.54K→25.19K

Class A Common Stock

Direct

S · Sale

−9.99K

Price / share

$137.25

Trade value

$1.37M

% of position

39.7%

8/3/2026

25.19K→15.20K

Class A Common Stock

Direct

S · Sale

−2.43K

Price / share

$138.09

Trade value

$335.69K

% of position

16.0%

8/3/2026

15.20K→12.77K

Class A Common Stock

Direct

S · Sale

−267.00

Price / share

$139.21

Trade value

$37.17K

% of position

2.1%

8/3/2026

12.77K→12.50K

Class A Common Stock

Direct

S · Sale

−84.00

Price / share

$133.00

Trade value

$11.17K

% of position

0.7%

8/3/2026

12.50K→12.42K

Class A Common Stock

Direct

S · Sale

−173.00

Price / share

$133.81

Trade value

$23.15K

% of position

1.4%

8/3/2026

12.42K→12.24K

Class A Common Stock

Direct

S · Sale

−44.00

Price / share

$135.41

Trade value

$5.96K

% of position

0.4%

8/3/2026

12.24K→12.20K

Class A Common Stock

Direct

S · Sale

−1.98K

Price / share

$136.42

Trade value

$270.26K

% of position

16.2%

8/3/2026

12.20K→10.22K

Class A Common Stock

Direct

S · Sale

−3.12K

Price / share

$137.25

Trade value

$428.75K

% of position

30.6%

8/3/2026

10.22K→7.09K

Class A Common Stock

Direct

S · Sale

−762.00

Price / share

$138.09

Trade value

$105.22K

% of position

10.7%

8/3/2026

7.09K→6.33K

Class A Common Stock

Direct

S · Sale

−82.00

Price / share

$139.21

Trade value

$11.42K

% of position

1.3%

8/3/2026

6.33K→6.25K

Class A Common Stock

Direct

S · Sale

−84.00

Price / share

$133.01

Trade value

$11.17K

% of position

1.3%

8/3/2026

6.25K→6.17K

Class A Common Stock

Direct

S · Sale

−173.00

Price / share

$133.81

Trade value

$23.15K

% of position

2.8%

8/3/2026

6.17K→5.99K

Class A Common Stock

Direct

S · Sale

−43.00

Price / share

$135.41

Trade value

$5.82K

% of position

0.7%

8/3/2026

5.99K→5.95K

Class A Common Stock

Direct

S · Sale

−1.98K

Price / share

$136.42

Trade value

$270.53K

% of position

33.3%

8/3/2026

5.95K→3.97K

Class A Common Stock

Direct

S · Sale

−3.13K

Price / share

$137.25

Trade value

$428.89K

% of position

78.8%

8/3/2026

3.97K→842.00

Class A Common Stock

Direct

S · Sale

−760.00

Price / share

$138.09

Trade value

$104.95K

% of position

90.3%

8/3/2026

842.00→82.00

Class A Common Stock

Direct

S · Sale

−82.00

Price / share

$139.20

Trade value

$11.41K

% of position

New position

8/3/2026

82.00→0.00

Class A Common Stock

Indirect

S · Sale

−6.25K

Price / share

$137.37

Trade value

$858.56K

% of position

3.6%

8/3/2026

175K→168.75K

Class A Common Stock

Indirect

S · Sale

−6.25K

Price / share

$137.37

Trade value

$858.56K

% of position

3.7%

8/3/2026

168.75K→162.50K

Total

Net shares

−12.50K

Net value

-$6.08M

Security	Date	Type	Shares	Price / Share	Trade Value	% of Position	Held Before	Held After
Class A Common Stock Direct	8/3/2026	M · Option Exercise	+20K	$2.80	$56K	New position	0.00	20K
Class A Common Stock Direct	8/3/2026	M · Option Exercise	+6.25K	$2.80	$17.50K	31.3%	20K	26.25K
Class A Common Stock Direct	8/3/2026	M · Option Exercise	+6.25K	$2.80	$17.50K	23.8%	26.25K	32.50K
Class A Common Stock Direct	8/3/2026	S · Sale	−269.00	$133.01	$35.78K	0.8%	32.50K	32.23K
Class A Common Stock Direct	8/3/2026	S · Sale	−555.00	$133.81	$74.26K	1.7%	32.23K	31.68K
Class A Common Stock Direct	8/3/2026	S · Sale	−135.00	$135.42	$18.28K	0.4%	31.68K	31.54K
Class A Common Stock Direct	8/3/2026	S · Sale	−6.35K	$136.42	$866.84K	20.1%	31.54K	25.19K
Class A Common Stock Direct	8/3/2026	S · Sale	−9.99K	$137.25	$1.37M	39.7%	25.19K	15.20K
Class A Common Stock Direct	8/3/2026	S · Sale	−2.43K	$138.09	$335.69K	16.0%	15.20K	12.77K
Class A Common Stock Direct	8/3/2026	S · Sale	−267.00	$139.21	$37.17K	2.1%	12.77K	12.50K
Class A Common Stock Direct	8/3/2026	S · Sale	−84.00	$133.00	$11.17K	0.7%	12.50K	12.42K
Class A Common Stock Direct	8/3/2026	S · Sale	−173.00	$133.81	$23.15K	1.4%	12.42K	12.24K
Class A Common Stock Direct	8/3/2026	S · Sale	−44.00	$135.41	$5.96K	0.4%	12.24K	12.20K
Class A Common Stock Direct	8/3/2026	S · Sale	−1.98K	$136.42	$270.26K	16.2%	12.20K	10.22K
Class A Common Stock Direct	8/3/2026	S · Sale	−3.12K	$137.25	$428.75K	30.6%	10.22K	7.09K
Class A Common Stock Direct	8/3/2026	S · Sale	−762.00	$138.09	$105.22K	10.7%	7.09K	6.33K
Class A Common Stock Direct	8/3/2026	S · Sale	−82.00	$139.21	$11.42K	1.3%	6.33K	6.25K
Class A Common Stock Direct	8/3/2026	S · Sale	−84.00	$133.01	$11.17K	1.3%	6.25K	6.17K
Class A Common Stock Direct	8/3/2026	S · Sale	−173.00	$133.81	$23.15K	2.8%	6.17K	5.99K
Class A Common Stock Direct	8/3/2026	S · Sale	−43.00	$135.41	$5.82K	0.7%	5.99K	5.95K
Class A Common Stock Direct	8/3/2026	S · Sale	−1.98K	$136.42	$270.53K	33.3%	5.95K	3.97K
Class A Common Stock Direct	8/3/2026	S · Sale	−3.13K	$137.25	$428.89K	78.8%	3.97K	842.00
Class A Common Stock Direct	8/3/2026	S · Sale	−760.00	$138.09	$104.95K	90.3%	842.00	82.00
Class A Common Stock Direct	8/3/2026	S · Sale	−82.00	$139.20	$11.41K	New position	82.00	0.00
Class A Common Stock Indirect	8/3/2026	S · Sale	−6.25K	$137.37	$858.56K	3.6%	175K	168.75K
Class A Common Stock Indirect	8/3/2026	S · Sale	−6.25K	$137.37	$858.56K	3.7%	168.75K	162.50K
Total			−12.50K		-$6.08M

Derivative Transactions3

Stock Option (right to buy)

Direct

M · Option Exercise

Converts to

Class A Common Stock

20K shares

−20K

Strike price

2.80

Held after

555K

Exercisable

—

8/3/2026

Stock Option (right to buy)

Direct

M · Option Exercise

Converts to

Class A Common Stock

6.25K shares

−6.25K

Strike price

2.80

Held after

548.75K

Exercisable

—

8/3/2026

Stock Option (right to buy)

Direct

M · Option Exercise

Converts to

Class A Common Stock

6.25K shares

−6.25K

Strike price

2.80

Held after

542.50K

Exercisable

—

8/3/2026

Security	Converts To	Date	Type	Shares	Strike Price	Exercisable	Held After
Stock Option (right to buy) Direct	Class A Common Stock20K shares	8/3/2026	M · Option Exercise	−20K	2.80	—	555K
Stock Option (right to buy) Direct	Class A Common Stock6.25K shares	8/3/2026	M · Option Exercise	−6.25K	2.80	—	548.75K
Stock Option (right to buy) Direct	Class A Common Stock6.25K shares	8/3/2026	M · Option Exercise	−6.25K	2.80	—	542.50K