Comparable stake leader
PRICE T ROWE ASSOCIATES INC /MD/
SEC ownership of Summit Materials, Inc.
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001621563.
Disclosed value leader
Argos SEM, LLC
Comparable rows
2/7
Latest evidence
31 Mar 2026
- Parsed ownership sources
-
13D/G, 13F, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
PRICE T ROWE ASSOCIATES INC /MD/
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
2 of 7
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
PRICE T ROWE ASSOCIATES INC /MD/
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
31 Mar 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001621563
- Issuer location
- Denver, CO
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of Summit Materials, Inc. (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
PRICE T ROWE ASSOCIATES I...
Disclosed value leader
Argos SEM, LLC
Comparable rows
2/7
Latest evidence
31 Mar 2026
13D/G
13F
3/4/5
Lead comparable stake: 3%
5 rows are not safely comparable across share classes.
13D/G row: PRICE T ROWE ASSOCIATES INC /MD/
Quick read
PRICE T ROWE ASSOCIATES INC /MD/ leads the comparable SEC ownership view at 3%.
2 of 7 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens PRICE T ROWE ASSOCIATES INC /MD/'s linked filing trail.
Comparable ownership
Top 2
PRICE T ROWE ASSOCIATES INC /MD/
3%
HUNTINGTON NATIONAL BANK
0%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-7 of 7 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| PRICE T ROWE ASSOCIATES INC /MD/ |
13D/G
T. Rowe Price Associates, Inc.
|
3%
|
$270,908,474
5,353,933 shares
|
$0 | 31 Dec 2024 |
| HUNTINGTON NATIONAL BANK |
13F
Company
|
0%
|
$105
2 shares
|
— | 31 Mar 2026 |
| Argos SEM, LLC |
3/4/5
Director, 10%+ Owner
|
—
mixed-class rows
|
$1,751,040,000
54,720,001 shares
mixed-class rows
|
— | 12 Jan 2024 |
| Brian James Harris |
3/4/5
EVP & Chief Financial Officer
|
—
mixed-class rows
|
$7,359,552
229,986 shares
mixed-class rows
|
— | 28 Feb 2023 |
| Kekin Ghelani |
3/4/5
Chief Strategy&Growth Officer
|
—
mixed-class rows
|
$1,293,707
30,390 shares
mixed-class rows
|
— | 07 Mar 2024 |
| John R. Murphy |
3/4/5
Director
|
—
class O/S missing
|
$687,968
21,499 shares
|
— | 29 Sep 2023 |
| Deon MacMillan |
3/4/5
EVP, Chief People Officer and Head of Corporate Communications
|
—
mixed-class rows
|
$413,536
12,923 shares
mixed-class rows
|
— | 10 Mar 2022 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Insider buy and sell flow is broadly balanced over the last 12 months. No Buy or Sell transactions have been reported since 17 Jun 2025.
Buys
$0
Insiders: 0
Sells
$0
Insiders: 0
Net
$0
Shares: 0
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 0
Shares: 0
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 0 | 0 | $0 | $0 | $0 |
| 3-6 | 0 | 0 | $0 | $0 | $0 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 0 | 0 | $0 | $0 | $0 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 25 reporting-owner rows connected to Summit Materials, Inc.. Open a relationship link for the CIK-to-CIK filing trail.
Rows
25
Largest Forms 3/4/5 holder
Argos SEM, LLC
Net 12M change
$0
Latest report
10 Feb 2025
Recent insider transactions for Summit Materials, Inc.
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| No insider transactions were found in the last 12 months for this issuer. | ||||||||||
* marks a reported price that did not pass the local price check.