Who owns West Pharmaceutical Services (WST)
Which tracked institutional funds hold WST, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See WST company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
The tracked-fund tape on WST is one-sided between 2026-Q1 and 2026-Q2: 390 added or opened and 93 trimmed or exited — on balance accumulating.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
WST’s largest tracked holder by dollar value, BlackRock, Inc., sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.1% of theirs — a 0.0pp gap the other way — the median holder sizes WST more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in WST divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2026-Q1 and 2026-Q2, across 776 tracked filers holding WST, 429 increased or opened the position and 359 reduced or closed it; over the same quarter, open-market insider Form 4s were net sales.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in WST between the 2026-Q1 and 2026-Q2 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
New buyers 59
- Boston Trust Walden Corp$29M
- ORBIMED ADVISORS LLC$25M
- CLOUGH CAPITAL PARTNERS L P$24M
- OSSIAM$19M
- CAPITOLIS LIQUID GLOBAL MARKETS LLC$13M
- Dakota Wealth Management$12M
Full exits 58
- T. Rowe Price Investment Management, Inc.$587M
- Amundi$161M
- VIKING GLOBAL INVESTORS LP$105M
- Border to Coast Pensions Partnership Ltd$57M
- Champlain Investment Partners, LLC$52M
- SG Americas Securities, LLC$29M
Largest adds
- BlackRock, Inc.$984M
- FMR LLC$970M
- VANGUARD CAPITAL MANAGEMENT LLC$482M
- VANGUARD PORTFOLIO MANAGEMENT LLC$416M
- STATE STREET CORP$377M
- GEODE CAPITAL MANAGEMENT, LLC$203M
Largest trims
- APG Asset Management N.V.$100M
- AMERICAN CENTURY COMPANIES INC$64M
- WORLDQUANT MILLENNIUM ADVISORS LLC$64M
- TWO SIGMA INVESTMENTS, LP$50M
- AQR CAPITAL MANAGEMENT LLC$46M
- RENAISSANCE TECHNOLOGIES LLC$41M
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| BlackRock, Inc. added | 6,651,784 | $2.4B | 10.8% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC trimmed | 4,613,134 | $1.7B | 7.5% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC trimmed | 4,015,766 | $1.4B | 6.5% | 2026-Q2 |
| FMR LLC added | 3,574,816 | $1.3B | 5.8% | 2026-Q2 |
| STATE STREET CORP added | 3,348,698 | $1.2B | 5.4% | 2026-Q2 |
| Artisan Partners Limited Partnership trimmed | 2,411,792 | $866M | 3.9% | 2026-Q2 |
| Bank of New York Mellon Corp trimmed | 2,043,823 | $734M | 3.3% | 2026-Q2 |
| GENERATION INVESTMENT MANAGEMENT LLP trimmed | 2,028,322 | $728M | 3.3% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC trimmed | 1,903,279 | $681M | 3.1% | 2026-Q2 |
| MORGAN STANLEY added | 1,582,546 | $568M | 2.6% | 2026-Q2 |
| JPMORGAN CHASE & CO added | 1,164,527 | $413M | 1.9% | 2026-Q2 |
| BROWN ADVISORY INC trimmed | 1,075,309 | $386M | 1.7% | 2026-Q2 |
| Longview Partners (Guernsey) LTD trimmed | 1,033,826 | $371M | 1.7% | 2026-Q2 |
| Invesco Ltd. trimmed | 1,009,852 | $363M | 1.6% | 2026-Q2 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC trimmed | 884,865 | $318M | 1.4% | 2026-Q2 |
| NORGES BANK trimmed | 862,915 | $310M | 1.4% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC added | 814,772 | $293M | 1.3% | 2026-Q2 |
| KAYNE ANDERSON RUDNICK INVESTMENT MANAGEMENT LLC trimmed | 760,622 | $273M | 1.2% | 2026-Q2 |
| TD Asset Management Inc trimmed | 731,054 | $262M | 1.2% | 2026-Q2 |
| NORTHERN TRUST CORP trimmed | 709,421 | $255M | 1.1% | 2026-Q2 |
| Capital Research Global Investors added | 609,221 | $219M | 1.0% | 2026-Q2 |
| VAN ECK ASSOCIATES CORP trimmed | 604,754 | $217M | 1.0% | 2026-Q2 |
| ProShare Advisors LLC trimmed | 598,024 | $215M | 1.0% | 2026-Q2 |
| Findlay Park Partners LLP trimmed | 596,646 | $214M | 1.0% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 583,984 | $210M | 0.9% | 2026-Q2 |
| Epoch Investment Partners, Inc. added | 562,557 | $202M | 0.9% | 2026-Q2 |
| APG Asset Management N.V. trimmed | 560,582 | $176M | 0.8% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ trimmed | 524,652 | $188M | 0.9% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 521,707 | $187M | 0.8% | 2026-Q2 |
| JACOBS LEVY EQUITY MANAGEMENT, INC trimmed | 507,786 | $182M | 0.8% | 2026-Q2 |
| SEI INVESTMENTS CO trimmed | 497,734 | $179M | 0.8% | 2026-Q2 |
| STATE FARM MUTUAL AUTOMOBILE INSURANCE CO added | 495,334 | $178M | 0.8% | 2026-Q2 |
| Legal & General Group Plc trimmed | 490,634 | $176M | 0.8% | 2026-Q2 |
| Nuveen, LLC added | 446,156 | $160M | 0.7% | 2026-Q2 |
| GATES FOUNDATION TRUST | 444,500 | $160M | 0.7% | 2026-Q2 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP trimmed | 438,718 | $157M | 0.7% | 2026-Q2 |
| ROYAL BANK OF CANADA added | 434,255 | $156M | 0.7% | 2026-Q2 |
| WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC added | 417,309 | $150M | 0.7% | 2026-Q2 |
| DEUTSCHE BANK AG\ trimmed | 410,699 | $147M | 0.7% | 2026-Q2 |
| Liontrust Investment Partners LLP added | 402,233 | $144M | 0.7% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO trimmed | 396,602 | $142M | 0.6% | 2026-Q2 |
| UBS Group AG added | 374,361 | $134M | 0.6% | 2026-Q2 |
| CITADEL ADVISORS LLC added | 352,769 | $127M | 0.6% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ trimmed | 350,482 | $126M | 0.6% | 2026-Q2 |
| Stonehage Fleming Financial Services Holdings Ltd added | 340,263 | $122M | 0.6% | 2026-Q2 |
| Quantinno Capital Management LP added | 308,116 | $111M | 0.5% | 2026-Q2 |
| Point72 Asset Management, L.P. added | 283,396 | $102M | 0.5% | 2026-Q2 |
| Holocene Advisors, LP added | 275,421 | $99M | 0.4% | 2026-Q2 |
| Russell Investments Group, Ltd. added | 271,862 | $98M | 0.4% | 2026-Q2 |
| ENVESTNET ASSET MANAGEMENT INC added | 259,536 | $93M | 0.4% | 2026-Q2 |
| BNP PARIBAS FINANCIAL MARKETS trimmed | 257,112 | $92M | 0.4% | 2026-Q2 |
| BARCLAYS PLC trimmed | 246,199 | $88M | 0.4% | 2026-Q2 |
| RHUMBLINE ADVISERS trimmed | 239,648 | $86M | 0.4% | 2026-Q2 |
| RIVERBRIDGE PARTNERS LLC trimmed | 232,514 | $83M | 0.4% | 2026-Q2 |
| LGT Group Foundation added | 223,365 | $80M | 0.4% | 2026-Q2 |
| JANE STREET GROUP, LLC trimmed | 217,581 | $78M | 0.4% | 2026-Q2 |
| BROWN BROTHERS HARRIMAN & CO trimmed | 206,212 | $74M | 0.3% | 2026-Q2 |
| Swiss National Bank trimmed | 203,160 | $73M | 0.3% | 2026-Q2 |
| FEDERATED HERMES, INC. trimmed | 197,269 | $71M | 0.3% | 2026-Q2 |
| CITIGROUP INC added | 190,778 | $68M | 0.3% | 2026-Q2 |
| Mitsubishi UFJ Asset Management Co., Ltd. added | 188,231 | $68M | 0.3% | 2026-Q2 |
| LOS ANGELES CAPITAL MANAGEMENT LLC added | 186,295 | $67M | 0.3% | 2026-Q2 |
| Vest Financial, LLC trimmed | 182,581 | $66M | 0.3% | 2026-Q2 |
| WELLINGTON MANAGEMENT GROUP LLP trimmed | 175,052 | $63M | 0.3% | 2026-Q2 |
| Sumitomo Mitsui Trust Group, Inc. trimmed | 168,080 | $60M | 0.3% | 2026-Q2 |
| Allianz Asset Management GmbH trimmed | 165,332 | $42M | 0.2% | 2026-Q2 |
| BAMCO INC /NY/ trimmed | 164,174 | $59M | 0.3% | 2026-Q2 |
| NOMURA ASSET MANAGEMENT CO LTD trimmed | 160,692 | $58M | 0.3% | 2026-Q2 |
| Birch Hill Investment Advisors LLC trimmed | 159,696 | $57M | 0.3% | 2026-Q2 |
| Vanguard Global Advisers, LLC trimmed | 152,124 | $55M | 0.2% | 2026-Q2 |
| BNP PARIBAS ASSET MANAGEMENT Holding S.A. added | 149,862 | $54M | 0.2% | 2026-Q2 |
| AMI ASSET MANAGEMENT CORP trimmed | 146,764 | $53M | 0.2% | 2026-Q2 |
| SCHRODER INVESTMENT MANAGEMENT GROUP added | 144,449 | $51M | 0.2% | 2026-Q2 |
| PRUDENTIAL FINANCIAL INC added | 143,328 | $51M | 0.2% | 2026-Q2 |
| HSBC HOLDINGS PLC trimmed | 138,384 | $50M | 0.2% | 2026-Q2 |
| Seilern Investment Management Ltd trimmed | 138,230 | $50M | 0.2% | 2026-Q2 |
| VANGUARD ASSET MANAGEMENT, Ltd added | 138,190 | $50M | 0.2% | 2026-Q2 |
| BANK OF MONTREAL /CAN/ added | 137,753 | $49M | 0.2% | 2026-Q2 |
| Local Pensions Partnership Investment Ltd added | 128,880 | $46M | 0.2% | 2026-Q2 |
| California Public Employees Retirement System trimmed | 127,799 | $46M | 0.2% | 2026-Q2 |
| National Pension Service added | 126,271 | $45M | 0.2% | 2026-Q2 |
| USS Investment Management Ltd added | 123,343 | $44M | 0.2% | 2026-Q2 |
| Susquehanna Portfolio Strategies, LLC added | 119,345 | $43M | 0.2% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 114,107 | $41M | 0.2% | 2026-Q2 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM added | 113,071 | $41M | 0.2% | 2026-Q2 |
| Conestoga Capital Advisors, LLC trimmed | 111,294 | $40M | 0.2% | 2026-Q2 |
| FIRST TRUST ADVISORS LP added | 108,546 | $39M | 0.2% | 2026-Q2 |
| TEACHER RETIREMENT SYSTEM OF TEXAS added | 104,511 | $38M | 0.2% | 2026-Q2 |
| AMERICAN CENTURY COMPANIES INC trimmed | 99,557 | $36M | 0.2% | 2026-Q2 |
| Candriam S.C.A. added | 96,349 | $35M | 0.2% | 2026-Q2 |
| Asset Management One Co., Ltd. added | 96,318 | $35M | 0.2% | 2026-Q2 |
| Ninety One UK Ltd trimmed | 93,032 | $33M | 0.2% | 2026-Q2 |
| RAYMOND JAMES FINANCIAL INC added | 92,072 | $33M | 0.1% | 2026-Q2 |
| Creative Planning added | 90,518 | $32M | 0.1% | 2026-Q2 |
| PRINCIPAL FINANCIAL GROUP INC added | 85,727 | $31M | 0.1% | 2026-Q2 |
| ROYAL LONDON ASSET MANAGEMENT LTD trimmed | 83,818 | $30M | 0.1% | 2026-Q2 |
| MARSHALL WACE, LLP added | 83,578 | $30M | 0.1% | 2026-Q2 |
| Boston Trust Walden Corp added | 81,231 | $29M | 0.1% | 2026-Q2 |
| Curi Capital, LLC added | 75,808 | $27M | 0.1% | 2026-Q2 |
| ORBIMED ADVISORS LLC new | 70,600 | $25M | 0.1% | 2026-Q2 |
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.