Mason Hawkins - Longleaf Partners 13F Activity & Position Changes (Q1 2026)

As of Mar 31, 2026, the Longleaf Partners portfolio activity showed several notable changes in holdings, according to the latest SEC 13F filing reported on May 15, 2026. The activity included new positions, additions to existing holdings, reductions, and complete exits, providing a clear view of how the portfolio evolved during the quarter.

During Q1 2026, the filing reported:

New Buys - None reported

Increases - Albertsons Companies, Inc., Clearwater Paper Corporation, New Oriental Education & Techno, Empire State Realty Trust, Inc., Fortune Brands Innovations, Inc, and 6 more

Reductions - ACM Research, Inc., Alexander's, Inc., Avantor, Inc., Bio-Rad Laboratories, Inc., Cardinal Health, Inc., and 10 more

Complete Exits - Walt Disney Company (The), Louisiana-Pacific Corporation, Owens & Minor, Inc., PotlatchDeltic Corporation - Co

These updates highlight how the portfolio adjusted across different sectors and market conditions, offering insights into allocation shifts and investment trends.

Date	Symbol	Name	Type	Change Qty	% Change	Value	Remaining
Q1 2026	ACI Albertsons Companies, Inc.	Albertsons Companies, Inc.	Buy	+1,253,089	+20.3%	$126.43M	7,419,801
Q1 2026	ACMR ACM Research, Inc.	ACM Research, Inc.	Sell	-897,281	-53.4%	$30.81M	782,900
Q1 2026	ALX Alexander's, Inc.	Alexander's, Inc.	Sell	-23,699	-19.3%	$23.39M	99,013
Q1 2026	AVTR Avantor, Inc.	Avantor, Inc.	Sell	-28,306	-0.8%	$27.60M	3,520,212
Q1 2026	BIO Bio-Rad Laboratories, Inc.	Bio-Rad Laboratories, Inc.	Sell	-64,826	-28.5%	$45.38M	162,804
Q1 2026	CAH Cardinal Health, Inc.	Cardinal Health, Inc.	Sell	-1,312	-15.2%	$1.55M	7,337
Q1 2026	CLW Clearwater Paper Corporation	Clearwater Paper Corporation	Buy	+144,561	+10.5%	$21.94M	1,525,491
Q1 2026	CNX CNX Resources Corporation	CNX Resources Corporation	Sell	-721,713	-15.2%	$154.74M	4,014,111
Q1 2026	DIS Walt Disney Company (The)	Walt Disney Company (The)	Sell - Position Exit	-317,175	-100.0%	$0.00	-
Q1 2026	EDU New Oriental Education & Techno	New Oriental Education & Techno	Buy	+142,719	+37.6%	$29.58M	522,280
Q1 2026	ESRT Empire State Realty Trust, Inc.	Empire State Realty Trust, Inc.	Buy	+2,769,081	+74.8%	$33.66M	6,473,317
Q1 2026	FBIN Fortune Brands Innovations, Inc	Fortune Brands Innovations, Inc	Buy	+975,182	+82.8%	$83.91M	2,153,285
Q1 2026	FDX FedEx Corporation	FedEx Corporation	Sell	-111,627	-31.1%	$88.15M	247,495
Q1 2026	FIS Fidelity National Information S	Fidelity National Information S	Buy	+205,352	+33.0%	$38.82M	827,501
Q1 2026	G9618E107 White Mountains	White Mountains	Sell	-12,788	-40.4%	$41.44M	18,864
Q1 2026	GHC Graham Holdings Company	Graham Holdings Company	Buy	+2,039	+5.7%	$39.92M	37,760
Q1 2026	IAC IAC Inc.	IAC Inc.	Buy	+33,389	+0.8%	$161.03M	4,022,729
Q1 2026	KHC The Kraft Heinz Company	The Kraft Heinz Company	Sell	-539,403	-12.0%	$88.81M	3,948,713
Q1 2026	LPX Louisiana-Pacific Corporation	Louisiana-Pacific Corporation	Sell - Position Exit	-272,123	-100.0%	$0.00	-
Q1 2026	MAT Mattel, Inc.	Mattel, Inc.	Buy	+4,241,829	+49.5%	$186.16M	12,812,157
Q1 2026	MGM MGM Resorts International	MGM Resorts International	Sell	-370,408	-18.2%	$61.55M	1,662,961
Q1 2026	OMI Owens & Minor, Inc.	Owens & Minor, Inc.	Sell - Position Exit	-181,735	-100.0%	$0.00	-
Q1 2026	PCH PotlatchDeltic Corporation - Co	PotlatchDeltic Corporation - Co	Sell - Position Exit	-3,162,963	-100.0%	$0.00	-
Q1 2026	PYPL PayPal Holdings, Inc.	PayPal Holdings, Inc.	Sell	-531,611	-95.9%	$1.02M	22,463
Q1 2026	REGN Regeneron Pharmaceuticals, Inc.	Regeneron Pharmaceuticals, Inc.	Sell	-35,130	-21.2%	$100.95M	130,662
Q1 2026	RYN Rayonier Inc. REIT	Rayonier Inc. REIT	Buy	+5,083,702	+89.5%	$221.93M	10,762,643
Q1 2026	SAM Boston Beer Company, Inc. (The)	Boston Beer Company, Inc. (The)	Sell	-29,596	-20.0%	$27.28M	118,401
Q1 2026	SN SharkNinja	SharkNinja	Sell	-38,600	-13.3%	$26.55M	250,666
Q1 2026	TRIP TripAdvisor, Inc.	TripAdvisor, Inc.	Buy	+1,759,811	+62.0%	$49.02M	4,598,068
Q1 2026	XPO XPO, Inc.	XPO, Inc.	Sell	-6,676	-51.3%	$1.23M	6,336

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