Security record · archived quarter
AMPH
Amphastar Pharmaceuticals, Inc. · Healthcare · Drug Manufacturers - Specialty & Generic
94Tracked holders
-1Δ holders
25.83MShares held
$677.54MReported value
+0New positions
−1Exits
Momentum inputs (comparable managers):
holder breadth -1.1% ·
share flow -0.7% ·
net new positions -1.1%
— formula
Broad distribution — falling shares and fewer holders
All ownership figures: tracked 13F managers only, common-stock positions, reporting period Q4 2025
Ownership over time
| Quarter | Holders | Δ | Shares | Reported value | New | Exits |
|---|---|---|---|---|---|---|
| Q2 2026 | 77 | -4 | 22.11M | $440.50M | +3 | −7 |
| Q1 2026 | 84 | -10 | 23.72M | $457.46M | +4 | −14 |
| Q4 2025 | 94 | -1 | 25.83M | $677.54M | — | −1 |
| Q3 2025 | 19 | 0 | 15.63M | $416.60M | — | — |
| Q2 2025 | 16 | +1 | 14.08M | $323.35M | +1 | — |
| Q1 2025 | 12 | -1 | 5.84M | $169.25M | — | −1 |
| Q4 2024 | 13 | 0 | 4.91M | $182.39M | — | — |
| Q3 2024 | 12 | +2 | 3.20M | $155.33M | +2 | — |
| Q2 2024 | 10 | — | 3.67M | $146.92M | — | — |
Who holds it · Q4 2025
| # | Manager | Shares | Δ shares | Value | Their weight | Held | ||
|---|---|---|---|---|---|---|---|---|
| 1 | BlackRock ✦ (passive) | 5.46M | -0.4% | $146.27M | 0.0% | ▼ Trim | 3 | SEC ↗ ×15 |
| 2 | The Vanguard Group ✦ (passive) | 2.61M | -0.9% | $69.85M | 0.0% | ▼ Trim | 3 | SEC ↗ ×6 |
| 3 | Td Asset Management Inc | 1.96M | — | $52.57M | 0.0% | n/c | 1 | SEC ↗ |
| 4 | Dimensional Fund Advisors Lp | 1.80M | — | $48.20M | 0.0% | n/c | 1 | SEC ↗ ×5 |
| 5 | State Street Global Advisors ✦ (passive) | 1.53M | +2.1% | $41.02M | 0.0% | ▲ Add | 5 | SEC ↗ |
| 6 | Marshall Wace ✦ | 1.24M | +41.5% | $33.13M | 0.0% | ▲ Add | 7 | SEC ↗ ×3 |
| 7 | Geode Capital Management ✦ (passive) | 886.83K | -3.9% | $23.75M | 0.0% | ▼ Trim | 7 | SEC ↗ ×2 |
| 8 | American Century Companies Inc | 665.34K | — | $17.82M | 0.0% | n/c | 1 | SEC ↗ |
| 9 | Morgan Stanley ✦ | 591.63K | +3.0% | $15.84M | 0.0% | ▲ Add | 2 | SEC ↗ ×11 |
| 10 | Arrowstreet Capital ✦ | 559.43K | +42.6% | $14.98M | 0.0% | ▲ Add | 3 | SEC ↗ |
| 11 | D. E. Shaw & Co. ✦ | 557.07K | +7.7% | $14.92M | 0.0% | ▲ Add | 6 | SEC ↗ ×2 |
| 12 | Goldman Sachs Group ✦ | 556.71K | +130.8% | $14.91M | 0.0% | ▲ Add | 2 | SEC ↗ ×3 |
| 13 | Renaissance Technologies ✦ | 544.70K | -7.2% | $14.59M | 0.0% | ▼ Trim | 7 | SEC ↗ |
| 14 | Invesco Ltd. | 501.40K | — | $13.43M | 0.0% | n/c | 1 | SEC ↗ ×5 |
| 15 | Hotchkis & Wiley Capital Management… | 402.56K | — | $10.78M | 0.0% | n/c | 1 | SEC ↗ |
| 16 | Northern Trust Corp | 371.39K | — | $9.95M | 0.0% | n/c | 1 | SEC ↗ ×7 |
| 17 | Charles Schwab Investment… | 350.71K | — | $9.39M | 0.0% | n/c | 1 | SEC ↗ |
| 18 | Victory Capital Management Inc | 305.16K | — | $8.17M | 0.0% | n/c | 1 | SEC ↗ |
| 19 | Millennium Management ✦ | 290.67K | -58.3% | $7.78M | 0.0% | ▼ Trim | 7 | SEC ↗ |
| 20 | Bank of New York Mellon Corp | 559.06K | — | $7.22M | 0.0% | n/c | 1 | SEC ↗ ×7 |
| 21 | UBS Group AG | 256.62K | — | $6.87M | 0.0% | n/c | 1 | SEC ↗ ×3 |
| 22 | Citadel Advisors ✦ | 228.72K | +0.9% | $6.13M | 0.0% | ▲ Add | 7 | SEC ↗ ×2 |
| 23 | Principal Financial Group Inc | 217.97K | — | $5.84M | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 24 | Jane Street Group, Llc | 217.54K | — | $5.83M | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 25 | Pacer Advisors, Inc. | 177.74K | — | $4.76M | 0.0% | n/c | 1 | SEC ↗ |
| 26 | JPMorgan Chase ✦ | 158.64K | -68.7% | $4.25M | 0.0% | ▼ Trim | 2 | SEC ↗ ×7 |
| 27 | First Trust Advisors Lp | 140.31K | — | $3.76M | 0.0% | n/c | 1 | SEC ↗ |
| 28 | Ameriprise Financial Inc | 133.72K | — | $3.58M | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 29 | Nordea Investment Management Ab | 129.14K | — | $3.46M | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 30 | Bank Of America Corp /De/ | 128.17K | — | $3.43M | 0.0% | n/c | 1 | SEC ↗ ×7 |
| 31 | New York State Common Retirement… | 125.97K | — | $3.37M | 0.0% | n/c | 1 | SEC ↗ |
| 32 | Bnp Paribas Financial Markets | 120.89K | — | $3.24M | 0.0% | n/c | 1 | SEC ↗ |
| 33 | Qube Research & Technologies Ltd | 111.44K | — | $2.98M | 0.0% | n/c | 1 | SEC ↗ |
| 34 | Two Sigma Investments ✦ | 98.68K | 0.0% | $2.64M | 0.0% | Held | 7 | SEC ↗ |
| 35 | Legal & General Group Plc | 90.73K | — | $2.43M | 0.0% | n/c | 1 | SEC ↗ ×3 |
| 36 | Raymond James Financial Inc | 84.45K | — | $2.26M | 0.0% | n/c | 1 | SEC ↗ ×4 |
| 37 | Rhumbline Advisers | 82.39K | — | $2.21M | 0.0% | n/c | 1 | SEC ↗ |
| 38 | Balyasny Asset Management L.P. | 77.47K | — | $2.07M | 0.0% | n/c | 1 | SEC ↗ |
| 39 | Nuveen, LLC | 76.10K | — | $2.04M | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 40 | Barclays Plc | 75.32K | — | $2.02M | 0.0% | n/c | 1 | SEC ↗ ×3 |
| 41 | Swiss National Bank | 72.60K | — | $1.94M | 0.0% | n/c | 1 | SEC ↗ |
| 42 | AQR Capital Management ✦ | 67.65K | +8.9% | $1.81M | 0.0% | ▲ Add | 7 | SEC ↗ ×6 |
| 43 | Cibc World Market Inc. | 62.19K | — | $1.67M | 0.0% | n/c | 1 | SEC ↗ |
| 44 | Alliancebernstein L.P. | 60.63K | — | $1.62M | 0.0% | n/c | 1 | SEC ↗ |
| 45 | UBS AM, a distinct business unit of… | 55.23K | — | $1.48M | 0.0% | n/c | 1 | SEC ↗ ×5 |
| 46 | Assetmark, Inc | 54.36K | — | $1.46M | 0.0% | n/c | 1 | SEC ↗ |
| 47 | Creative Planning | 51.66K | — | $1.38M | 0.0% | n/c | 1 | SEC ↗ |
| 48 | Prudential Financial Inc | 47.20K | — | $1.26M | 0.0% | n/c | 1 | SEC ↗ |
| 49 | Wells Fargo & Company/Mn | 45.30K | — | $1.21M | 0.0% | n/c | 1 | SEC ↗ ×3 |
| 50 | T. Rowe Price ✦ | 36.80K | -86.6% | $986,000 | 0.0% | ▼ Trim | 7 | SEC ↗ |
| 51 | California State Teachers… | 35.80K | — | $958,670 | 0.0% | n/c | 1 | SEC ↗ |
| 52 | Canada Pension Plan Investment Board | 29.80K | — | $798,044 | 0.0% | n/c | 1 | SEC ↗ |
| 53 | Deutsche Bank Ag\ | 29.56K | — | $791,537 | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 54 | Universal- Beteiligungs- und… | 29.10K | — | $785,265 | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 55 | Envestnet Asset Management Inc | 28.82K | — | $771,880 | 0.0% | n/c | 1 | SEC ↗ |
| 56 | Citigroup Inc | 28.28K | — | $757,338 | 0.0% | n/c | 1 | SEC ↗ ×4 |
| 57 | Gotham Asset Management ✦ | 27.80K | +81.0% | $744,538 | 0.0% | ▲ Add | 7 | SEC ↗ |
| 58 | Franklin Resources Inc | 26.05K | — | $697,484 | 0.0% | n/c | 1 | SEC ↗ ×3 |
| 59 | Federated Hermes, Inc. | 23.54K | — | $630,321 | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 60 | Corient Private Wealth LP | 23.18K | — | $620,716 | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 61 | LPL Financial LLC | 19.84K | — | $531,422 | 0.0% | n/c | 1 | SEC ↗ |
| 62 | Sei Investments Co | 153.65K | — | $520,464 | 0.0% | n/c | 1 | SEC ↗ ×3 |
| 63 | State Of Wisconsin Investment Board | 17.51K | — | $468,811 | 0.0% | n/c | 1 | SEC ↗ |
| 64 | MIRAE ASSET GLOBAL ETFS HOLDINGS… | 16.88K | — | $452,020 | 0.0% | n/c | 1 | SEC ↗ |
| 65 | Janus Henderson Group Plc | 16.87K | — | $451,809 | 0.0% | n/c | 1 | SEC ↗ |
| 66 | Manufacturers Life Insurance… | 16.40K | — | $439,246 | 0.0% | n/c | 1 | SEC ↗ |
| 67 | Quantinno Capital Management LP | 15.57K | — | $416,911 | 0.0% | n/c | 1 | SEC ↗ |
| 68 | Assenagon Asset Management S.A. | 15.22K | — | $407,484 | 0.0% | n/c | 1 | SEC ↗ |
| 69 | Squarepoint Ops LLC | 14.86K | — | $397,951 | 0.0% | n/c | 1 | SEC ↗ |
| 70 | Mml Investors Services, Llc | 14.66K | — | $392,622 | 0.0% | n/c | 1 | SEC ↗ |
| 71 | Man Group plc | 14.15K | — | $378,964 | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 72 | Osaic Holdings, Inc. | 12.85K | — | $344,228 | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 73 | State Board Of Administration Of… | 10.91K | — | $292,250 | 0.0% | n/c | 1 | SEC ↗ |
| 74 | Royal Bank Of Canada | 9.27K | — | $248,000 | 0.0% | n/c | 1 | SEC ↗ ×8 |
| 75 | ProShare Advisors LLC | 9.08K | — | $243,242 | 0.0% | n/c | 1 | SEC ↗ |
| 76 | Commonwealth Equity Services, Llc | 8.74K | — | $234,110 | 0.0% | n/c | 1 | SEC ↗ |
| 77 | Susquehanna International Group, Llp | 8.13K | — | $217,802 | 0.0% | n/c | 1 | SEC ↗ |
| 78 | Zurcher Kantonalbank (Zurich… | 7.50K | — | $200,957 | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 79 | Pnc Financial Services Group, Inc. | 5.81K | — | $155,538 | 0.0% | n/c | 1 | SEC ↗ ×4 |
| 80 | Cetera Investment Advisers | 111.00K | — | $102,353 | 0.0% | n/c | 1 | SEC ↗ |
| 81 | BNP Paribas Asset Management… | 3.76K | — | $101,000 | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 82 | Russell Investments Group, Ltd. | 3.73K | — | $99,862 | 0.0% | n/c | 1 | SEC ↗ ×5 |
| 83 | Fidelity (FMR) ✦ | 3.52K | -45.6% | $94,338 | 0.0% | ▼ Trim | 3 | SEC ↗ ×3 |
| 84 | Mirae Asset Global Investments Co.… | 2.23K | — | $59,800 | 0.0% | n/c | 1 | SEC ↗ |
| 85 | Group One Trading Llc | 1.74K | — | $46,624 | 0.0% | n/c | 1 | SEC ↗ |
| 86 | Cwm, Llc | 1.68K | — | $45,000 | 0.0% | n/c | 1 | SEC ↗ |
| 87 | Lazard Asset Management Llc | 912 | — | $24,423 | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 88 | Us Bancorp \De\ | 806 | — | $21,585 | 0.0% | n/c | 1 | SEC ↗ ×2 |
| 89 | Jones Financial Companies Lllp | 531 | — | $14,220 | 0.0% | n/c | 1 | SEC ↗ |
| 90 | Fifth Third Bancorp | 509 | — | $13,631 | 0.0% | n/c | 1 | SEC ↗ |
| 91 | Daiwa Securities Group Inc. | 135 | — | $4,000 | 0.0% | n/c | 1 | SEC ↗ |
| 92 | Rockefeller Capital Management L.P. | 100 | — | $2,678 | 0.0% | n/c | 1 | SEC ↗ |
| 93 | Optiver Holding B.V. | 64 | — | $1,714 | 0.0% | n/c | 1 | SEC ↗ |
| 94 | Kayne Anderson Rudnick Investment… | 15 | — | $402 | 0.0% | n/c | 1 | SEC ↗ |
“Their weight” = the position's share of that manager's reported 13F equity value — the conviction measure. ✦ = curated manager.
New buyers
| No new tracked buyers this quarter. |
Exited
| Wellington Management | $458,353 | was 0.0% |
Full-market context: across ALL 13F filers (SEC structured data, Q1 2026): 212 holders, 31.98M shares, $604.53M reported. This is a different, older period than the tracked-universe figures above and the two are never mixed.
Frequently co-owned
What else this security's tracked holders most often hold — shared-ownership counts, not fundamental relationships.
Open-market purchases (P)
No open-market insider purchases in our coverage window.
Open-market sales (S)
Sep 21
PETERS WILLIAM J
Officer, Director · 4.14K sh · $103,475
Sep 16
Zhou Rong
Officer · 10.00K sh · $239,404
Sep 02
Zhou Rong
Officer · 3.19K sh · $75,306
Aug 11
PRINS RICHARD K
Director · 7.97K sh · $161,852
Aug 07
PETERS WILLIAM J
Officer, Director · 8.18K sh · $183,886
Awards, exercises and tax withholding are never counted as buys or sales here. Methodology
Jul 14
SC 13G — DIMENSIONAL FUND ADVISORS LP
Provenance: Ownership from parsed 13F common-stock positions (tracked universe, comparable sets for changes); insider rows from Forms 3/4/5; stakes from Schedules 13D/13G; every filing links to its original on SEC EDGAR.
Reporting period: Q4 2025 ·
Methodology ·
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