West Pharmaceutical Services, Inc.
MX ˙ BMV ˙ US9553061055
SecurityMX:WST / West Pharmaceutical Services, Inc.
InstitutionDimensional Fund Advisors Lp
Latest Disclosed Ownership461,462 shares
Latest Disclosed Value $ 115,639,545
Dimensional Fund Advisors Lp reports 5.51% increase in ownership of WST / West Pharmaceutical Services, Inc.

On May 7, 2026 - Dimensional Fund Advisors Lp filed a 13F-HR form disclosing ownership of 461,462 shares of West Pharmaceutical Services, Inc. (MX:WST) valued at $115,639,545 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 437,360 shares of West Pharmaceutical Services, Inc.. This represents a change in shares of 5.51% during the quarter.

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)
2026-05-07 2026-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 461,462 24,102 5.51 115,640 -3.91 0.0052
2026-02-12 2025-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 437,360 56,454 14.82 120,341 20.44 0.0252
2025-11-12 2025-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 380,906 65,132 20.63 99,916 44.61 0.0214
2025-08-12 2025-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 315,774 -3,504 -1.10 69,094 -3.33 0.0160
2025-05-13 2025-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 319,278 44,445 16.17 71,472 -20.61 0.0178
2025-02-13 2024-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 274,833 1,999 0.73 90,028 9.91 0.0216
2024-11-07 2024-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 272,834 -15,805 -5.48 81,913 -13.84 0.0199
2024-08-09 2024-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 288,639 30,253 11.71 95,075 -7.01 0.0248
2024-05-10 2024-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 258,386 -11,206 -4.16 102,246 7.70 0.0277
2024-02-07 2023-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 269,592 -165 -0.06 94,934 -6.21 0.0277
2023-11-09 2023-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 269,757 -23,880 -8.13 101,225 -9.86 0.0332
2023-08-09 2023-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 293,637 1,461 0.50 112,302 10.95 0.0358
2023-05-12 2023-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 292,176 259 0.09 101,222 148,755.88 0.0341
2023-02-09 2022-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 291,917 -6,749 -2.26 69 -99.91 0.0203
2022-11-10 2022-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 298,666 4,726 1.61 73,505 -17.29 0.0282
2022-08-12 2022-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 293,940 -11,710 -3.83 88,869 -29.21 0.0319
2022-05-13 2022-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 305,650 -12,892 -4.05 125,543 -15.97 0.0387
2022-02-09 2021-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 318,542 3,067 0.97 149,402 11.54 0.0452
2021-11-12 2021-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 315,475 -4,345 -1.36 133,943 16.63 0.0431
2021-08-12 2021-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 319,820 -2,973 -0.92 114,848 26.27 0.0364
2021-05-14 2021-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 322,793 -1,557 -0.48 90,952 -1.02 0.0301
2021-03-08 2020-12-31 13F/A-2 WEST PHARMACEUTICAL SVSC COM 955306105 324,350 -21,143 -6.12 91,886 -3.25 0.0332
2021-02-11 2020-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 324,350 -21,143 91,886 33,184.3392
2020-11-12 2020-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 345,493 -899 -0.26 94,973 20.71 0.0403
2020-08-13 2020-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 346,392 25,506 7.95 78,676 61.05 0.0346
2020-05-14 2020-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 320,886 -9,809 -2.97 48,853 -1.73 0.0255
2020-02-14 2019-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 330,695 -7,324 -2.17 49,714 3.71 0.0181
2019-11-12 2019-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 338,019 -4,327 -1.26 47,936 11.89 0.0186
2019-08-13 2019-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 342,346 -7,807 -2.23 42,842 11.04 0.0166
2019-08-12 2019-03-31 13F/A-2 WEST PHARMACEUTICAL SVSC COM 955306105 350,153 -3,418 -0.97 38,583 11.32 0.0154
2019-05-10 2019-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 350,153 -3,418 38,583
2019-02-26 2018-12-31 13F/A-1 WEST PHARMACEUTICAL SVSC COM 955306105 353,571 4,225 1.21 34,658 -19.65 0.0157
2019-02-13 2018-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 353,571 4,225 34,658
2018-11-13 2018-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 349,346 7,877 2.31 43,132 27.22 0.0164
2018-08-10 2018-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 341,469 9,774 2.95 33,904 15.77 0.0135
2018-05-11 2018-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 331,695 13,752 4.33 29,285 -6.66 0.0122
2018-02-12 2017-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 317,943 -18,084 -5.38 31,373 -3.01 0.0130
2017-11-13 2017-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 336,027 -5,770 -1.69 32,346 0.12 0.0141
2017-08-11 2017-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 341,797 -4,432 -1.28 32,307 14.34 0.0149
2017-05-12 2017-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 346,229 -25,432 -6.84 28,256 -10.38 0.0135
2017-02-09 2016-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 371,661 -31,903 -7.91 31,529 4.87 0.0157
2016-11-10 2016-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 403,564 -15,027 -3.59 30,064 -5.34 0.0162
2016-08-09 2016-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 418,591 934 0.22 31,760 9.71 0.0183
2016-05-13 2016-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 417,657 -148,618 -26.24 28,950 -15.11 0.0173
2016-02-10 2015-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 566,275 -93,945 -14.23 34,104 -4.56 0.0213
2015-11-13 2015-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 660,220 -146,904 -18.20 35,732 -23.78 0.0235
2015-08-14 2015-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 807,124 -124,570 -13.37 46,878 -16.43 0.0287
2015-05-14 2015-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 931,694 30,355 3.37 56,095 16.89 0.0354
2015-02-06 2014-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 901,339 19,809 2.25 47,988 21.62 0.0315
2014-11-13 2014-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 881,530 -25,578 -2.82 39,458 3.13 0.0280
2014-08-08 2014-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 907,108 -13,896 -1.51 38,262 -5.68 0.0266
2014-05-14 2014-03-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 921,004 -12,168 -1.30 40,567 -11.39 0.0303
2014-02-12 2013-12-31 13F WEST PHARMACEUTICAL SVSC COM 955306105 933,172 -4,656 -0.50 45,781 18.63 0.0357
2013-11-13 2013-09-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 937,828 446,368 90.82 38,591 11.76 0.0334
2013-08-15 2013-06-30 13F WEST PHARMACEUTICAL SVSC COM 955306105 491,460 491,460 34,530 0.0325
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.