Mountaineer Partners Management’s Builders FirstSource BLDR Stock Holding History

Mountaineer Partners Management’s Portfolio BLDR Stock Details BLDR Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	$8.09M	Buy	98,203 +4,112	+4%	+$439K	4.02%	13
2025 Q4	$9.68M	Buy	94,091 +33,332	+55%	+$3.75M	5.42%	10
2025 Q3	$7.37M	Sell	60,759 -1,705	-3%	-$226K	4.28%	12
2025 Q2	$7.29M	Buy	62,464 +4,253	+7%	+$491K	4.82%	13
2025 Q1	$7.27M	Buy	58,211 +2,336	+4%	+$340K	6.96%	9
2024 Q4	$7.99M	Hold	55,875	–	–	5.85%	11
2024 Q3	$10.8M	Buy	+55,875	New	+$9.27M	6.75%	5
2021 Q1	–	Sell	-250,327	Closed	-$10.2M	–	17
2020 Q4	$10.2M	Sell	250,327 -47,540	-16%	-$1.68M	7.33%	2
2020 Q3	$9.72M	Buy	297,867 +28,600	+11%	+$776K	8.39%	2
2020 Q2	$5.57M	Sell	269,267 -3,000	-1%	-$54.2K	7.48%	5
2020 Q1	$3.33M	Sell	272,267 -50,233	-16%	-$1.13M	4.74%	8
2019 Q4	$8.19M	Sell	322,500 -43,800	-12%	-$1.05M	9.12%	5
2019 Q3	$7.54M	Sell	366,300 -145,000	-28%	-$2.7M	7.59%	7
2019 Q2	$8.62M	Sell	511,300 -26,800	-5%	-$401K	3.98%	11
2019 Q1	$7.18M	Buy	538,100 +11,500	+2%	+$151K	6.13%	11
2018 Q4	$5.75M	Buy	+526,600	New	+$6.62M	4.89%	11

Other funds holding BLDR

BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return

VCM

Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM

State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return

VPM

Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM

Wellington Management Group Boston, Massachusetts $535B AUM 26.23% 1-Year Est. Return

Dimensional Fund Advisors Austin, Texas $481B AUM 30.42% 1-Year Est. Return

Capital International Investors Los Angeles, California $427B AUM 29.17% 1-Year Est. Return

Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return

Sands Capital Management Arlington, Virginia $25.5B AUM 26.46% 1-Year Est. Return

Invesco Atlanta, Georgia $1.02T AUM 30.18% 1-Year Est. Return

Mountaineer Partners Management's BLDR Position: Q1 2026 in Review

Mountaineer Partners Management increased its Builders FirstSource (BLDR) stake by 4.4% in Q1 2026, buying an estimated $439K and bringing the position to 98,203 shares worth $8.09M. The position accounts for 4.02% of the portfolio, ranked #13.

Mountaineer Partners Management first reported a position in BLDR in Q4 2018 and has held it in 16 quarters since. The position peaked at $10.8M in Q3 2024. 719 funds tracked by Wall St. Rank hold BLDR as of Q1 2026.

Mountaineer Partners Management held 98,203 shares of Builders FirstSource worth $8.09M as of Q1 2026.
Mountaineer Partners Management bought 4,112 Builders FirstSource shares in Q1 2026, an estimated $439K.
Builders FirstSource made up 4.02% of Mountaineer Partners Management's portfolio in Q1 2026, its #13 holding.
Mountaineer Partners Management first reported a position in Builders FirstSource in Q4 2018 and has held it in 16 quarters since.
Mountaineer Partners Management's Builders FirstSource position peaked at $10.8M in Q3 2024.
719 funds tracked by Wall St. Rank held Builders FirstSource as of Q1 2026.

Based on Mountaineer Partners Management's 13F filing for Q1 2026, filed 15 May 2026.