Form 13-F position report

AVANTOR INC COM

Reported by SOUTHEASTERN ASSET MANAGEMENT INC TN

AVTR CUSIP 05352A100 Manager CIK 0000807985

First reported at 5,149,420 shares this quarter.

New
% of reported 13F value 3.28% This manager · Q3 2025
Shares 5,149,420 Quarter-end amount reported
Reported value $64,264,762 Fair value at quarter end
Consecutive quarters held 1 Through Q3 2025

Reported position value by quarter

Reported position value by quarter

Each bar is a Form 13-F quarter-end snapshot. It does not show trades made within the quarter.

Reported position value by quarter
Date Holding Value
2025-09-30 64264762
2025-12-31 40666017
2026-03-31 27598462
2026-06-30 46782232

Quarterly position history

How this manager's reported quarter-end position changed over time.

4 quarters
Quarterly reported position history for AVANTOR INC COM held by SOUTHEASTERN ASSET MANAGEMENT INC TN.
Quarter Activity Shares Change % of reported 13F Reported value Filed Source filing
Q2 2026 Added 4,725,478 +1,205,266 (34.2%) 2.44% $46,782,232 2026-08-14
Q1 2026 Reduced 3,520,212 -28,306 (-0.8%) 1.36% $27,598,462 2026-05-15
Q4 2025 Reduced 3,548,518 -1,600,902 (-31.1%) 1.81% $40,666,017 2026-02-13
Q3 2025 New 5,149,420 +5,149,420 (0.0%) 3.28% $64,264,762 2025-11-14

Who else reported the position

583 managers reported AVANTOR INC COM for Q3 2025.

Managers reporting AVANTOR INC COM in Q3 2025.
Manager Activity Shares Change % of reported 13F Reported value Tenure
Dodge & Cox Added 117,746,888 +313,404 0.79% $1,469,481,162 9 qtrs
VANGUARD GROUP INC Added 65,988,977 +1,135,279 0.01% $823,542,433 26 qtrs
BlackRock Inc Reduced 60,716,987 -11,188,159 0.01% $757,747,993 5 qtrs
BARROW HANLEY MEWHINNEY & STRAUSS LLC Added 34,548,129 +3,356,861 1.37% $431,160,650 11 qtrs
T Rowe Price Investment Management Inc Reduced 32,927,695 -23,573,020 0.25% $410,938,000 13 qtrs
STATE STREET CORPORATION Reduced 20,365,770 -3,118,996 < 0.01% $254,164,810 26 qtrs
Engine Capital Management LP Added 19,720,430 +14,216,121 29.22% $246,110,966 2 qtrs
GREENHAVEN ASSOCIATES INC New 18,311,570 +18,311,570 3.48% $228,528,394 1 qtr
Invesco Ltd Added 16,053,368 +119,508 0.03% $200,346,033 26 qtrs
Clarkston Capital Partners LLC Added 15,020,325 +1,038,235 4.04% $187,453,656 11 qtrs
Premium adds each manager's conviction percentile across reporting peers.
Filing details and methodology As reported
Report period
September 30, 2025
Filed
November 14, 2025
Filing type
13F-HR
Position type
COM

Voting authority reported

Sole
5,114,035
Shared
0
None
35,385

“None” means the manager reported no voting authority for those shares on non-routine matters. It does not disclose why and is not evidence of securities lending.

Form 13-F is a delayed quarter-end snapshot of disclosed long Section 13(f) securities. It can be filed up to 45 days after quarter end, excludes short positions and most non-U.S. securities, and does not reveal intra-quarter trading. For options, reported shares and value describe the underlying-share exposure; strike, expiry, premium, and written positions are not disclosed.