West Pharmaceutical Services, Inc.
US ˙ NYSE ˙ US9553061055

SecurityWST / West Pharmaceutical Services, Inc.
InstitutionNatixis Advisors, L.p.
Latest Disclosed Ownership62,572 shares
Latest Disclosed Value $ 15,683
Natixis Advisors, L.p. reports 19.63% increase in ownership of WST / West Pharmaceutical Services, Inc.

On May 13, 2026 - Natixis Advisors, L.p. filed a 13F-HR form disclosing ownership of 62,572 shares of West Pharmaceutical Services, Inc. (US:WST) valued at $15,683,046 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 52,304 shares of West Pharmaceutical Services, Inc.. This represents a change in shares of 19.63% during the quarter. The current value of the position is $19,792,149 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)
2026-05-13 2026-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 62,572 10,268 19.63 16 7.14 0.0218
2026-02-10 2025-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 52,304 -4,558 -8.02 14 0.00 0.0204
2025-11-13 2025-09-30 13F WEST PHARMACEUTICAL SVSC INC COM 955306105 56,862 500 0.89 15 16.67 0.0218
2025-08-13 2025-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 56,362 -3,114 -5.24 12 -7.69 0.0196
2025-05-08 2025-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 59,476 -942 -1.56 13 -31.58 0.0246
2025-02-10 2024-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 60,418 6,671 12.41 20 18.75 0.0370
2024-11-06 2024-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 53,747 4,740 9.67 16 0.00 0.0315
2024-08-01 2024-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 49,007 -5,904 -10.75 16 -23.81 0.0351
2024-04-25 2024-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 54,911 8,353 17.94 22 31.25 0.0500
2024-02-06 2023-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 46,558 -3,375 -6.76 16 -11.11 0.0432
2023-11-13 2023-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 49,933 5,954 13.54 19 12.50 0.0573
2023-08-15 2023-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 43,979 647 1.49 17 6.67 0.0519
2023-05-11 2023-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 43,332 3,684 9.29 15 66.67 0.0517
2023-01-27 2022-12-31 13F WEST PHARMACEUTICAL SVS COM 955306105 39,648 -16,098 -28.88 9 -99.93 0.0353
2022-11-14 2022-09-30 13F WEST PHARMACEUTICAL SVCS COM 955306105 55,746 959 1.75 13,718 -17.19 0.0580
2022-08-12 2022-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 54,787 -9,283 -14.49 16,566 -37.04 0.0728
2022-05-12 2022-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 64,070 2,448 3.97 26,314 -8.95 0.1003
2022-02-08 2021-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 61,622 6,513 11.82 28,901 23.53 0.1104
2021-11-15 2021-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 55,109 -5,182 -8.59 23,396 8.06 0.0962
2021-08-12 2021-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 60,291 3,374 5.93 21,650 34.99 0.1011
2021-05-05 2021-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 56,917 6,217 12.26 16,038 11.65 0.0837
2021-02-12 2020-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 50,700 2,182 4.50 14,364 7.69 0.0827
2020-11-12 2020-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 48,518 -3,178 -6.15 13,338 13.57 0.0839
2020-08-11 2020-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 51,696 12,820 32.98 11,744 98.41 0.0779
2020-04-27 2020-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 38,876 22,306 134.62 5,919 137.62 0.0482
2020-02-10 2019-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 16,570 1,371 9.02 2,491 15.54 0.0176
2019-11-12 2019-09-30 13F WEST PHARM SVCS COM 955306105 15,199 -5,301 -25.86 2,156 -15.95 0.0171
2019-08-12 2019-06-30 13F WEST PHARM SVCS COM 955306105 20,500 -1,375 -6.29 2,565 6.43 0.0209
2019-05-15 2019-03-31 13F/A-1 WEST PHARM SVCS COM 955306105 21,875 11,485 110.54 2,410 136.51 0.0211
2019-05-15 2019-03-31 13F WEST PHARM SVCS COM 955306105 21,875 11,485 2,410
2019-02-13 2018-12-31 13F/A-1 WEST PHARMACEUTICAL SVSC COM 955306105 10,390 10,390 1,019 0.0101
2019-02-13 2018-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 10,390 10,390 1,019
2018-05-10 2018-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 0 -12,594 -100.00 0 -100.00
2018-02-14 2017-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 12,594 749 6.32 1,243 9.04 0.0127
2017-11-14 2017-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 11,845 1,443 13.87 1,140 15.97 0.0120
2017-07-27 2017-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 10,402 -148 -1.40 983 14.17 0.0106
2017-05-12 2017-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 10,550 -181 -1.69 861 -5.38 0.0095
2017-02-07 2016-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 10,731 5,896 121.94 910 283.97 0.0109
2014-02-12 2013-12-31 13F WEST PHARMACEUTICAL COM 955306105 4,835 4,835 237 0.0039
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.