Avantor, Inc.
US ˙ NYSE ˙ US05352A1007

SecurityAVTR / Avantor, Inc.
InstitutionSei Investments Co
Latest Disclosed Ownership5,241,143 shares
Latest Disclosed Value $ 60,063,519
Sei Investments Co reports 14.85% increase in ownership of AVTR / Avantor, Inc.

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 5,241,143 shares of Avantor, Inc. (US:AVTR) valued at $60,063,499 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 4,563,468 shares of Avantor, Inc.. This represents a change in shares of 14.85% during the quarter. The current value of the position is $49,895,681 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.

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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)
2026-02-13 2025-12-31 13F AVANTOR COM 05352A100 5,241,143 677,675 14.85 60,064 5.46 0.0593
2025-11-13 2025-09-30 13F AVANTOR COM 05352A100 4,563,468 157,309 3.57 56,952 -3.97 0.0612
2025-08-14 2025-06-30 13F AVANTOR COM 05352A100 4,406,159 2,860,016 184.98 59,307 136.64 0.0687
2025-05-14 2025-03-31 13F/A-1 AVANTOR COM 05352A100 1,546,143 91,643 6.30 25,063 -18.22 0.0323
2025-05-13 2025-03-31 13F AVANTOR COM 05352A100 1,453,982 -518 30,626 0.0333
2025-02-11 2024-12-31 13F AVANTOR COM 05352A100 1,454,500 285,704 24.44 30,646 1.36 0.0394
2024-11-12 2024-09-30 13F AVANTOR COM 05352A100 1,168,796 188,852 19.27 30,237 45.55 0.0393
2024-08-13 2024-06-30 13F AVANTOR COM 05352A100 979,944 300,125 44.15 20,775 19.51 0.0294
2024-05-07 2024-03-31 13F AVANTOR COM 05352A100 679,819 92,877 15.82 17,383 29.73 0.0255
2024-02-14 2023-12-31 13F AVANTOR COM 05352A100 586,942 -32,426 -5.24 13,400 2.63 0.0215
2023-11-14 2023-09-30 13F AVANTOR COM 05352A100 619,368 -397,638 -39.10 13,056 -37.50 0.0235
2023-08-11 2023-06-30 13F AVANTOR COM 05352A100 1,017,006 -34,430 -3.27 20,889 -6.02 0.0364
2023-05-12 2023-03-31 13F AVANTOR COM 05352A100 1,051,436 336,171 47.00 22,227 47.35 0.0413
2023-02-10 2022-12-31 13F AVANTOR COM 05352A100 715,265 -40,143 -5.31 15,085 1.88 0.0335
2022-11-14 2022-09-30 13F AVANTOR COM 05352A100 755,408 -40,311 -5.07 14,806 -40.03 0.0330
2022-08-15 2022-06-30 13F AVANTOR COM 05352A100 795,719 192,393 31.89 24,691 20.85 0.0533
2022-05-13 2022-03-31 13F AVANTOR COM 05352A100 603,326 6,719 1.13 20,431 -18.87 0.0411
2022-02-14 2021-12-31 13F AVANTOR COM 05352A100 596,607 113,803 23.57 25,182 27.25 0.0472
2021-11-12 2021-09-30 13F AVANTOR COM 05352A100 482,804 36,895 8.27 19,789 24.37 0.0415
2021-08-06 2021-06-30 13F AVANTOR COM 05352A100 445,909 157,629 54.68 15,911 91.68 0.0353
2021-05-12 2021-03-31 13F AVANTOR COM 05352A100 288,280 136,739 90.23 8,301 95.46 0.0209
2021-02-08 2020-12-31 13F AVANTOR COM 05352A100 151,541 5,033 3.44 4,247 33.43 0.0110
2020-12-04 2020-09-30 13F/A-1 AVANTOR COM 05352A100 146,508 44,228 43.24 3,183 107.50 0.0092
2020-11-06 2020-09-30 13F AVANTOR COM 05352A100 147,209 44,929 3,199 7,702.4807
2020-08-17 2020-06-30 13F/A-1 AVANTOR COM 05352A100 102,280 33,392 48.47 1,534 79.42 0.0048
2020-08-11 2020-06-30 13F AVANTOR COM 05352A100 42,983 -25,905 547 1,483.7666
2020-05-14 2020-03-31 13F AVANTOR COM 05352A100 68,888 48,786 242.69 855 137.50 0.0031
2020-02-06 2019-12-31 13F AVANTOR COM 05352A100 20,102 5,772 40.28 360 70.62 0.0011
2019-11-12 2019-09-30 13F AVANTOR COM 05352A100 14,330 4,030 39.13 211 7.11 0.0005
2019-08-14 2019-06-30 13F AVANTOR COM 05352A100 10,300 10,300 197 0.0006
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.