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Security record · archived quarter

AMPH

Amphastar Pharmaceuticals, Inc. · Healthcare · Drug Manufacturers - Specialty & Generic

25.87 -2.1% mkt cap $1.10B quote delayed (FMP) · as of Oct 18 03:59 UTC · separate from filing data below

Q3 2026 Q2 2026 Q1 2026 Q4 2025 Q3 2025 Q2 2025 Q1 2025 Q4 2024
84Tracked holders
-10Δ holders
23.72MShares held
$457.46MReported value
+4New positions
−14Exits
Strongly Falling Conviction score 27/100 How these are computed → Explain this at the Research Desk →

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
QuarterHoldersΔSharesReported valueNewExits
Q3 2026 1 0 15.22K $392,725 n/a n/a
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 n/a −1
Q3 2025 19 0 15.63M $416.60M n/a n/a
Q2 2025 16 +1 14.08M $323.35M +1 n/a
Q1 2025 12 -1 5.84M $169.25M n/a −1
Q4 2024 13 0 4.91M $182.39M n/a n/a
Q3 2024 12 +2 3.20M $155.33M +2 n/a
Q2 2024 10 n/a 3.67M $146.92M n/a n/a
Holder count
Who holds it · Q1 2026
#ManagerSharesΔ sharesValueTheir weightHeld
1 BlackRock ✦ (passive) 5.42M -0.7% $106.20M 0.0% ▼ Trim 4 SEC ↗ ×15
2 Dimensional Fund Advisors Lp 2.03M +12.7% $39.73M 0.0% ▲ Add 2 SEC ↗ ×5
3 State Street Global Advisors ✦ (passive) 1.61M +4.9% $31.49M 0.0% ▲ Add 6 SEC ↗
4 Vanguard Capital Management Llc 1.54M n/a $30.24M 0.0% n/c 1 SEC ↗
5 Td Asset Management Inc 1.54M -21.5% $30.19M 0.0% ▼ Trim 2 SEC ↗
6 Marshall Wace ✦ 1.03M -17.1% $20.09M 0.0% ▼ Trim 8 SEC ↗ ×3
7 American Century Companies Inc 1.02M +52.9% $19.93M 0.0% ▲ Add 2 SEC ↗
8 Geode Capital Management ✦ (passive) 976.65K +10.1% $19.14M 0.0% ▲ Add 8 SEC ↗ ×2
9 D. E. Shaw & Co. ✦ 665.54K +19.5% $13.04M 0.0% ▲ Add 7 SEC ↗ ×2
10 Invesco Ltd. 604.77K +20.6% $11.85M 0.0% ▲ Add 2 SEC ↗ ×4
11 Renaissance Technologies ✦ 553.90K +1.7% $10.85M 0.0% ▲ Add 8 SEC ↗
12 Morgan Stanley ✦ 420.34K -28.9% $8.23M 0.0% ▼ Trim 3 SEC ↗ ×10
13 UBS Group AG 420.26K +63.8% $8.23M 0.0% ▲ Add 2 SEC ↗ ×4
14 Northern Trust Corp 372.28K +0.2% $7.29M 0.0% ▲ Add 2 SEC ↗ ×7
15 Millennium Management ✦ 371.37K +27.8% $7.28M 0.0% ▲ Add 8 SEC ↗
16 Goldman Sachs Group ✦ 329.39K -40.8% $6.45M 0.0% ▼ Trim 3 SEC ↗ ×3
17 Arrowstreet Capital ✦ 325.29K -41.9% $6.37M 0.0% ▼ Trim 4 SEC ↗
18 Charles Schwab Investment… 321.04K -8.5% $6.29M 0.0% ▼ Trim 2 SEC ↗
19 Pacer Advisors, Inc. 261.48K +47.1% $5.12M 0.0% ▲ Add 2 SEC ↗
20 Bank of New York Mellon Corp 543.23K -2.8% $5.04M 0.0% ▼ Trim 2 SEC ↗ ×7
21 Victory Capital Management Inc 249.62K -18.2% $4.89M 0.0% ▼ Trim 2 SEC ↗
22 Principal Financial Group Inc 209.13K -4.1% $4.10M 0.0% ▼ Trim 2 SEC ↗ ×2
23 Bank Of America Corp /De/ 174.32K +36.0% $3.41M 0.0% ▲ Add 2 SEC ↗ ×3
24 Bnp Paribas Financial Markets 156.08K +29.1% $3.06M 0.0% ▲ Add 2 SEC ↗
25 First Trust Advisors Lp 150.59K +7.3% $2.95M 0.0% ▲ Add 2 SEC ↗
26 New York State Common Retirement… 148.72K +18.1% $2.91M 0.0% ▲ Add 2 SEC ↗
27 Universal- Beteiligungs- und… 139.40K +379.0% $2.73M 0.0% ▲ Add 2 SEC ↗ ×2
28 Franklin Resources Inc 139.31K +434.9% $2.73M 0.0% ▲ Add 2 SEC ↗ ×4
29 Two Sigma Investments ✦ 138.15K +40.0% $2.71M 0.0% ▲ Add 8 SEC ↗
30 Nordea Investment Management Ab 123.82K -4.1% $2.42M 0.0% ▼ Trim 2 SEC ↗ ×2
31 JPMorgan Chase ✦ 104.57K -34.1% $2.01M 0.0% ▼ Trim 3 SEC ↗ ×7
32 Jane Street Group, Llc 92.47K -57.5% $1.81M 0.0% ▼ Trim 2 SEC ↗ ×2
33 Rhumbline Advisers 83.72K +1.6% $1.64M 0.0% ▲ Add 2 SEC ↗
34 Legal & General Group Plc 80.92K -10.8% $1.59M 0.0% ▼ Trim 2 SEC ↗ ×3
35 AQR Capital Management ✦ 78.78K +16.4% $1.54M 0.0% ▲ Add 8 SEC ↗ ×5
36 Ameriprise Financial Inc 78.78K -41.1% $1.54M 0.0% ▼ Trim 2 SEC ↗ ×2
37 Alliancebernstein L.P. 56.43K -6.9% $1.51M 0.0% ▼ Trim 2 SEC ↗
38 Nuveen, LLC 76.59K +0.7% $1.50M 0.0% ▲ Add 2 SEC ↗ ×2
39 Swiss National Bank 72.60K 0.0% $1.42M 0.0% Held 2 SEC ↗
40 Robeco Institutional Asset… 66.41K New $1.30M 0.0% New 1 SEC ↗
41 Citadel Advisors ✦ 65.54K -71.3% $1.28M 0.0% ▼ Trim 8 SEC ↗
42 Hrt Financial Lp 56.18K New $1.10M 0.0% New 1 SEC ↗
43 UBS AM, a distinct business unit of… 55.38K +0.3% $1.08M 0.0% ▲ Add 2 SEC ↗ ×5
44 Assetmark, Inc 53.74K -1.1% $1.05M 0.0% ▼ Trim 2 SEC ↗
45 Prudential Financial Inc 50.69K +7.4% $993,076 0.0% ▲ Add 2 SEC ↗
46 T. Rowe Price ✦ 44.90K +22.0% $880,000 0.0% ▲ Add 8 SEC ↗
47 Wells Fargo & Company/Mn 42.02K -7.2% $823,149 0.0% ▼ Trim 2 SEC ↗ ×4
48 Hsbc Holdings Plc 38.02K New $753,497 0.0% New 1 SEC ↗
49 Man Group plc 37.27K +163.4% $730,198 0.0% ▲ Add 2 SEC ↗ ×2
50 Citigroup Inc 35.90K +27.0% $703,359 0.0% ▲ Add 2 SEC ↗ ×4
51 Deutsche Bank Ag\ 33.13K +12.1% $649,036 0.0% ▲ Add 2 SEC ↗ ×2
52 Squarepoint Ops LLC 28.34K +90.8% $555,279 0.0% ▲ Add 2 SEC ↗
53 California State Teachers… 28.30K -20.9% $554,377 0.0% ▼ Trim 2 SEC ↗
54 Barclays Plc 21.28K -71.7% $416,934 0.0% ▼ Trim 2 SEC ↗ ×4
55 Raymond James Financial Inc 19.05K -77.4% $373,288 0.0% ▼ Trim 2 SEC ↗ ×4
56 Envestnet Asset Management Inc 18.27K -36.6% $357,870 0.0% ▼ Trim 2 SEC ↗
57 State Of Wisconsin Investment Board 17.39K -0.7% $340,631 0.0% ▼ Trim 2 SEC ↗
58 Janus Henderson Group Plc 16.87K 0.0% $330,697 0.0% Held 2 SEC ↗
59 MIRAE ASSET GLOBAL ETFS HOLDINGS… 16.85K -0.2% $330,013 0.0% ▼ Trim 2 SEC ↗
60 Creative Planning 16.40K -68.2% $321,335 0.0% ▼ Trim 2 SEC ↗
61 Canada Pension Plan Investment Board 16.30K -45.3% $319,317 0.0% ▼ Trim 2 SEC ↗
62 Manufacturers Life Insurance… 15.88K -3.2% $311,070 0.0% ▼ Trim 2 SEC ↗
63 Assenagon Asset Management S.A. 15.22K 0.0% $298,081 0.0% Held 2 SEC ↗
64 Susquehanna International Group, Llp 14.60K +79.5% $286,034 0.0% ▲ Add 2 SEC ↗
65 Federated Hermes, Inc. 14.08K -40.2% $275,808 0.0% ▼ Trim 2 SEC ↗ ×3
66 Osaic Holdings, Inc. 13.04K +1.4% $255,450 0.0% ▲ Add 2 SEC ↗ ×2
67 Mml Investors Services, Llc 12.37K -15.7% $242,270 0.0% ▼ Trim 2 SEC ↗
68 State Board Of Administration Of… 10.91K 0.0% $213,786 0.0% Held 2 SEC ↗
69 Fifth Third Bancorp 8.75K +1619.1% $171,418 0.0% ▲ Add 2 SEC ↗ ×2
70 Zurcher Kantonalbank (Zurich… 7.78K +3.7% $152,469 0.0% ▲ Add 2 SEC ↗
71 Pnc Financial Services Group, Inc. 5.45K -6.2% $106,745 0.0% ▼ Trim 2 SEC ↗ ×4
72 Cetera Investment Advisers 111.00K 0.0% $100,289 0.0% Held 2 SEC ↗
73 Royal Bank Of Canada 3.52K -62.0% $68,000 0.0% ▼ Trim 2 SEC ↗ ×6
74 Russell Investments Group, Ltd. 3.44K -7.6% $67,487 0.0% ▼ Trim 2 SEC ↗ ×5
75 Mirae Asset Global Investments Co.… 2.37K +6.0% $46,350 0.0% ▲ Add 2 SEC ↗
76 Fidelity (FMR) ✦ 1.29K -63.3% $25,353 0.0% ▼ Trim 4 SEC ↗ ×3
77 Cwm, Llc 658 -60.9% $12,890 0.0% ▼ Trim 2 SEC ↗
78 BNP Paribas Asset Management… 396 -89.5% $7,758 0.0% ▼ Trim 2 SEC ↗
79 Us Bancorp \De\ 318 -60.5% $6,230 0.0% ▼ Trim 2 SEC ↗
80 Jones Financial Companies Lllp 288 -45.8% $5,475 0.0% ▼ Trim 2 SEC ↗
81 Simplex Trading, Llc 262 New $5,132 0.0% New 1 SEC ↗
82 Group One Trading Llc 214 -87.7% $4,192 0.0% ▼ Trim 2 SEC ↗
83 Rockefeller Capital Management L.P. 124 +24.0% $2,429 0.0% ▲ Add 2 SEC ↗ ×2
84 Optiver Holding B.V. 28 -56.2% $549 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

Robeco Institutional Asset… $1.30M 0.0%
Hrt Financial Lp $1.10M 0.0%
Hsbc Holdings Plc $753,497 0.0%
Simplex Trading, Llc $5,132 0.0%

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): 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.

Insider transactions

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

Beneficial ownership
Jul 14 SC 13G: DIMENSIONAL FUND ADVISORS LP

View original SEC filing ↗

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 · Get this via the API