Builders FirstSource, Inc.
DE ˙ DB ˙ US12008R1077
64,22 € ↓ −0,04 (−0,06%)
2026-06-03
DELAT PRIS
SecurityDE:B1F / Builders FirstSource, Inc.
InstitutionMackenzie Financial Corp
Latest Disclosed Ownership67,615 shares
Latest Disclosed Value $ 5,566,743
Mackenzie Financial Corp reports 420.68% increase in ownership of B1F / Builders FirstSource, Inc.

On May 13, 2026 - Mackenzie Financial Corp filed a 13F-HR form disclosing ownership of 67,615 shares of Builders FirstSource, Inc. (DE:B1F) valued at $4,669,492 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 18, 2026 disclosing 12,986 shares of Builders FirstSource, Inc.. This represents a change in shares of 420.68% during the quarter. The current value of the position is $4,342,235 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

Upgrade to unlock premium data and export to Excel .

Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-13 2026-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 67,615 54,629 420.68 5,567 316.31 0.0067
2026-02-18 2025-12-31 13F BUILDERS FIRSTSOURCE COM 12008R107 12,986 -1,348 -9.40 1,337 -23.03 0.0016
2025-11-13 2025-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 14,334 -5,778 -28.73 1,738 -25.96 0.0021
2025-08-13 2025-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 20,112 5,541 38.03 2,347 28.90 0.0030
2025-05-07 2025-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 14,571 569 4.06 1,821 -9.05 0.0026
2025-05-02 2024-12-31 13F/A-2 BUILDERS FIRSTSOURCE COM 12008R107 14,002 3,647 35.22 2,001 -0.30 0.0027
2025-02-20 2024-12-31 13F/A-1 BUILDERS FIRSTSOURCE COM 12008R107 14,002 3,647 2,001 0.0026
2025-02-14 2024-12-31 13F Builders FirstSource Common Stock 12008R107 14,002 3,647 2,004 0.0029
2024-11-13 2024-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 10,355 -8,860 -46.11 2,007 -24.52 0.0028
2024-08-14 2024-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 19,215 -7,928 -29.21 2,660 -53.02 0.0040
2024-05-10 2024-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 27,143 -79,799 -74.62 5,661 -68.29 0.0082
2024-01-30 2023-12-31 13F BUILDERS FIRSTSOURCE COM 12008R107 106,942 -41,116 -27.77 17,853 2.90 0.0269
2023-10-25 2023-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 148,058 18,898 14.63 17,349 -1.47 0.0292
2023-08-03 2023-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 129,160 -24,049 -15.70 17,608 29.46 0.0267
2023-04-24 2023-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 153,209 143,857 1,538.25 13,602 2,144.39 0.0210
2023-02-14 2022-12-31 13F BUILDERS FIRSTSOURCE COM 12008R107 9,352 -4,216 -31.07 607 -24.16 0.0010
2022-10-07 2022-09-30 13F Builders FirstSource Common Stock 12008R107 13,568 9,678 248.79 799 282.30 0.0014
2022-08-10 2022-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 3,890 3,890 209 0.0003
2021-02-10 2020-12-31 13F BUILDERS FIRSTSOURCE COM 12008R107 0 -7,220 -100.00 0 -100.00
2020-11-13 2020-09-30 13F BUILDERS FIRSTSOURCE COM 12008R107 7,220 -16,848 -70.00 236 -52.61 0.0006
2020-08-13 2020-06-30 13F BUILDERS FIRSTSOURCE COM 12008R107 24,068 -10,789 -30.95 498 16.90 0.0013
2020-05-14 2020-03-31 13F BUILDERS FIRSTSOURCE COM 12008R107 34,857 34,857 426 0.0014
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.