KILGORE JASON (See Remarks) exercised options at SUMMIT MATERIALS, INC.

Option exercise — a mechanical event triggered by vesting or expiry. Not a discretionary conviction trade.

M · 3 exercises

KILGORE JASON

Filed: 3/4/2024ACC: 0001628280-24-008676

InsiderKILGORE JASONCIK 2006214

→

IssuerSUMMIT MATERIALS, INC.CIK 1621563

Officer· See Remarks

Since Jan 2024

-2.65K

Net shares

Net seller

$113.3K

Total sold

Open market trades

0B · 0S

Total transactions

8.80K acquired · 11.45K disposed

Non-Derivative Transactions4

Class A Common Stock

Direct

M · Option Exercise

+2.79K

Price / share

—

Trade value

—

% of position

6.2%

2/29/2024

44.99K→47.77K

Class A Common Stock

Direct

M · Option Exercise

+2.80K

Price / share

—

Trade value

—

% of position

5.9%

2/29/2024

47.77K→50.57K

Class A Common Stock

Direct

M · Option Exercise

+3.22K

Price / share

—

Trade value

—

% of position

6.4%

2/29/2024

50.57K→53.79K

Class A Common Stock

Direct

F · Tax Withholding

−2.65K

Price / share

$42.71

Trade value

$113.27K

% of position

4.9%

2/29/2024

53.79K→51.13K

Total

Net shares

+6.15K

Net value

-$113.27K

Security	Date	Type	Shares	Price / Share	Trade Value	% of Position	Held Before	Held After
Class A Common Stock Direct	2/29/2024	M · Option Exercise	+2.79K	—	—	6.2%	44.99K	47.77K
Class A Common Stock Direct	2/29/2024	M · Option Exercise	+2.80K	—	—	5.9%	47.77K	50.57K
Class A Common Stock Direct	2/29/2024	M · Option Exercise	+3.22K	—	—	6.4%	50.57K	53.79K
Class A Common Stock Direct	2/29/2024	F · Tax Withholding	−2.65K	$42.71	$113.27K	4.9%	53.79K	51.13K
Total			+6.15K		-$113.27K

Derivative Transactions3

Restricted Stock Units

Direct

M · Option Exercise

Converts to

Class A Common Stock

2.79K shares

−2.79K

Strike price

Held after

0.00

Exercisable

—

2/29/2024

Restricted Stock Units

Direct

M · Option Exercise

Converts to

Class A Common Stock

2.80K shares

−2.80K

Strike price

Held after

2.79K

Exercisable

—

2/29/2024

Restricted Stock Units

Direct

M · Option Exercise

Converts to

Class A Common Stock

3.22K shares

−3.22K

Strike price

Held after

6.43K

Exercisable

—

2/29/2024

Security	Converts To	Date	Type	Shares	Exercisable	Held After
Restricted Stock Units Direct	Class A Common Stock2.79K shares	2/29/2024	M · Option Exercise	−2.79K	—	0.00
Restricted Stock Units Direct	Class A Common Stock2.80K shares	2/29/2024	M · Option Exercise	−2.80K	—	2.79K
Restricted Stock Units Direct	Class A Common Stock3.22K shares	2/29/2024	M · Option Exercise	−3.22K	—	6.43K

Non-Derivative Holdings (Post-Transaction)1

Class A Common Stock

Indirect

Shares owned108.64K

Total

108.64K indirect108.64K

Security Title	Shares Owned	Ownership Type
Class A Common Stock	108.64K	Indirect
Total	108.64K	108.64K indirect

Derivative Holdings (Post-Transaction)0

No derivative holdings reported