Security record · archived quarter
AMPH
Amphastar Pharmaceuticals, Inc. · Healthcare · Drug Manufacturers - Specialty & Generic
84Tracked holders
-10Δ holders
23.72MShares held
$457.46MReported value
+4New positions
−14Exits
Momentum inputs (comparable managers):
holder breadth -10.6% ·
share flow -4.2% ·
net new positions -11.9%
— formula
Broad distribution — falling shares and fewer holders
All ownership figures: tracked 13F managers only, common-stock positions, reporting period Q1 2026
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 · Q1 2026
| # | Manager | Shares | Δ shares | Value | Their weight | Held | ||
|---|---|---|---|---|---|---|---|---|
| 1 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 2 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 3 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 4 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 5 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 6 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 7 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 8 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 9 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 10 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 11 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 12 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 13 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 14 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 15 | BlackRock ✦ (passive) | 5.42M | -0.7% | $106.20M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 16 | Dimensional Fund Advisors Lp | 2.03M | +12.7% | $39.73M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 17 | Dimensional Fund Advisors Lp | 2.03M | +12.7% | $39.73M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 18 | Dimensional Fund Advisors Lp | 2.03M | +12.7% | $39.73M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 19 | Dimensional Fund Advisors Lp | 2.03M | +12.7% | $39.73M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 20 | Dimensional Fund Advisors Lp | 2.03M | +12.7% | $39.73M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 21 | State Street Global Advisors ✦ (passive) | 1.61M | +4.9% | $31.49M | 0.0% | ▲ Add | 6 | SEC ↗ |
| 22 | Vanguard Capital Management Llc | 1.54M | — | $30.24M | 0.0% | n/c | 1 | SEC ↗ |
| 23 | Td Asset Management Inc | 1.54M | -21.5% | $30.19M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 24 | Marshall Wace ✦ | 1.03M | -17.1% | $20.09M | 0.0% | ▼ Trim | 8 | SEC ↗ |
| 25 | Marshall Wace ✦ | 1.03M | -17.1% | $20.09M | 0.0% | ▼ Trim | 8 | SEC ↗ |
| 26 | Marshall Wace ✦ | 1.03M | -17.1% | $20.09M | 0.0% | ▼ Trim | 8 | SEC ↗ |
| 27 | American Century Companies Inc | 1.02M | +52.9% | $19.93M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 28 | Geode Capital Management ✦ (passive) | 976.65K | +10.1% | $19.14M | 0.0% | ▲ Add | 8 | SEC ↗ |
| 29 | Geode Capital Management ✦ (passive) | 976.65K | +10.1% | $19.14M | 0.0% | ▲ Add | 8 | SEC ↗ |
| 30 | D. E. Shaw & Co. ✦ | 665.54K | +19.5% | $13.04M | 0.0% | ▲ Add | 7 | SEC ↗ |
| 31 | D. E. Shaw & Co. ✦ | 665.54K | +19.5% | $13.04M | 0.0% | ▲ Add | 7 | SEC ↗ |
| 32 | Invesco Ltd. | 604.77K | +20.6% | $11.85M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 33 | Invesco Ltd. | 604.77K | +20.6% | $11.85M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 34 | Invesco Ltd. | 604.77K | +20.6% | $11.85M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 35 | Invesco Ltd. | 604.77K | +20.6% | $11.85M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 36 | Renaissance Technologies ✦ | 553.90K | +1.7% | $10.85M | 0.0% | ▲ Add | 8 | SEC ↗ |
| 37 | Morgan Stanley ✦ | 420.34K | -28.9% | $8.23M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 38 | Morgan Stanley ✦ | 420.34K | -28.9% | $8.23M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 39 | Morgan Stanley ✦ | 420.34K | -28.9% | $8.23M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 40 | Morgan Stanley ✦ | 420.34K | -28.9% | $8.23M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 41 | Morgan Stanley ✦ | 420.34K | -28.9% | $8.23M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 42 | Morgan Stanley ✦ | 420.34K | -28.9% | $8.23M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 43 | Morgan Stanley ✦ | 420.34K | -28.9% | $8.23M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 44 | Morgan Stanley ✦ | 420.34K | -28.9% | $8.23M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 45 | Morgan Stanley ✦ | 420.34K | -28.9% | $8.23M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 46 | Morgan Stanley ✦ | 420.34K | -28.9% | $8.23M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 47 | UBS Group AG | 420.26K | +63.8% | $8.23M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 48 | UBS Group AG | 420.26K | +63.8% | $8.23M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 49 | UBS Group AG | 420.26K | +63.8% | $8.23M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 50 | UBS Group AG | 420.26K | +63.8% | $8.23M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 51 | Northern Trust Corp | 372.28K | +0.2% | $7.29M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 52 | Northern Trust Corp | 372.28K | +0.2% | $7.29M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 53 | Northern Trust Corp | 372.28K | +0.2% | $7.29M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 54 | Northern Trust Corp | 372.28K | +0.2% | $7.29M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 55 | Northern Trust Corp | 372.28K | +0.2% | $7.29M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 56 | Northern Trust Corp | 372.28K | +0.2% | $7.29M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 57 | Northern Trust Corp | 372.28K | +0.2% | $7.29M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 58 | Millennium Management ✦ | 371.37K | +27.8% | $7.28M | 0.0% | ▲ Add | 8 | SEC ↗ |
| 59 | Goldman Sachs Group ✦ | 329.39K | -40.8% | $6.45M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 60 | Goldman Sachs Group ✦ | 329.39K | -40.8% | $6.45M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 61 | Goldman Sachs Group ✦ | 329.39K | -40.8% | $6.45M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 62 | Arrowstreet Capital ✦ | 325.29K | -41.9% | $6.37M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 63 | Charles Schwab Investment… | 321.04K | -8.5% | $6.29M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 64 | Pacer Advisors, Inc. | 261.48K | +47.1% | $5.12M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 65 | Bank of New York Mellon Corp | 543.23K | -2.8% | $5.04M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 66 | Bank of New York Mellon Corp | 543.23K | -2.8% | $5.04M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 67 | Bank of New York Mellon Corp | 543.23K | -2.8% | $5.04M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 68 | Bank of New York Mellon Corp | 543.23K | -2.8% | $5.04M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 69 | Bank of New York Mellon Corp | 543.23K | -2.8% | $5.04M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 70 | Bank of New York Mellon Corp | 543.23K | -2.8% | $5.04M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 71 | Bank of New York Mellon Corp | 543.23K | -2.8% | $5.04M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 72 | Victory Capital Management Inc | 249.62K | -18.2% | $4.89M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 73 | Principal Financial Group Inc | 209.13K | -4.1% | $4.10M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 74 | Principal Financial Group Inc | 209.13K | -4.1% | $4.10M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 75 | Bank Of America Corp /De/ | 174.32K | +36.0% | $3.41M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 76 | Bank Of America Corp /De/ | 174.32K | +36.0% | $3.41M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 77 | Bank Of America Corp /De/ | 174.32K | +36.0% | $3.41M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 78 | Bnp Paribas Financial Markets | 156.08K | +29.1% | $3.06M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 79 | First Trust Advisors Lp | 150.59K | +7.3% | $2.95M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 80 | New York State Common Retirement… | 148.72K | +18.1% | $2.91M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 81 | Universal- Beteiligungs- und… | 139.40K | +379.0% | $2.73M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 82 | Universal- Beteiligungs- und… | 139.40K | +379.0% | $2.73M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 83 | Franklin Resources Inc | 139.31K | +434.9% | $2.73M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 84 | Franklin Resources Inc | 139.31K | +434.9% | $2.73M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 85 | Franklin Resources Inc | 139.31K | +434.9% | $2.73M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 86 | Franklin Resources Inc | 139.31K | +434.9% | $2.73M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 87 | Two Sigma Investments ✦ | 138.15K | +40.0% | $2.71M | 0.0% | ▲ Add | 8 | SEC ↗ |
| 88 | Nordea Investment Management Ab | 123.82K | -4.1% | $2.42M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 89 | Nordea Investment Management Ab | 123.82K | -4.1% | $2.42M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 90 | JPMorgan Chase ✦ | 104.57K | -34.1% | $2.01M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 91 | JPMorgan Chase ✦ | 104.57K | -34.1% | $2.01M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 92 | JPMorgan Chase ✦ | 104.57K | -34.1% | $2.01M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 93 | JPMorgan Chase ✦ | 104.57K | -34.1% | $2.01M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 94 | JPMorgan Chase ✦ | 104.57K | -34.1% | $2.01M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 95 | JPMorgan Chase ✦ | 104.57K | -34.1% | $2.01M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 96 | JPMorgan Chase ✦ | 104.57K | -34.1% | $2.01M | 0.0% | ▼ Trim | 3 | SEC ↗ |
| 97 | Jane Street Group, Llc | 92.47K | -57.5% | $1.81M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 98 | Jane Street Group, Llc | 92.47K | -57.5% | $1.81M | 0.0% | ▼ Trim | 2 | SEC ↗ |
| 99 | Rhumbline Advisers | 83.72K | +1.6% | $1.64M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 100 | Legal & General Group Plc | 80.92K | -10.8% | $1.59M | 0.0% | ▼ Trim | 2 | 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
| Hotchkis & Wiley Capital… | $10.78M | was 0.0% |
| Qube Research & Technologies… | $2.98M | was 0.0% |
| Balyasny Asset Management L.P. | $2.07M | was 0.0% |
| Cibc World Market Inc. | $1.67M | was 0.0% |
| Gotham Asset Management | $744,538 | was 0.0% |
| Corient Private Wealth LP | $620,716 | was 0.0% |
| LPL Financial LLC | $531,422 | was 0.0% |
| Sei Investments Co | $520,464 | was 0.0% |
| Quantinno Capital Management… | $416,911 | was 0.0% |
| ProShare Advisors LLC | $243,242 | was 0.0% |
| Commonwealth Equity Services… | $234,110 | was 0.0% |
| Lazard Asset Management Llc | $24,423 | was 0.0% |
Full-market context: across ALL 13F filers (SEC structured data, Q1 2026): 5 holders, 1.03M shares, $928,379 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)
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: Q1 2026 ·
Methodology ·
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