Security key
03209R103
Amphastar Pharmaceuticals, Inc. - Common Stock (AMPH)
CUSIP: 03209R103
Q1 2026 13F Holders as of 31 Mar 2026
- Type / Class
- Equity / Common Stock
- Shares outstanding
- 46,377,939
- Total 13F shares
- 32,080,880
- Share change
- -1,420,606
- Total reported value
- $628,812,947
- Price per share
- $19.59
- Number of holders
- 211
- Value change
- -$38,909,010
- Number of buys
- 88
- Number of sells
- 137
Report period
Q1 2026
Institutions
211
Top holders
10
AMPH full security history
Previous quarter: Q4 2025
Amphastar Pharmaceuticals, Inc. SEC filings
Amphastar Pharmaceuticals, Inc. company facts
Broader feeds
Reporting periods
Holder history for CUSIP 03209R103
Recent filing periods:
Top shareholders of AMPH - Amphastar Pharmaceuticals, Inc. - Common Stock (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Ownership % is shown only when it is directly reported or safely comparable across share classes.
Methodology: rows are grouped by holder and ranked by the holder's primary source value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
| Holder | Source | Role / Reporting | Ownership % | Shares | Holdings Value | 12M Net Δ | As of | Details |
|---|---|---|---|---|---|---|---|---|
| Jack Y. Zhang |
13D/G
3/4/5
|
CEO & CHIEF SCIENTIFIC OFFICER, Director, 10%+ Owner |
25%
|
12,524,153
|
$301,456,363 | $0 | 31 Dec 2024 | |
| BlackRock, Inc. |
13F
13D/G
|
Company |
12%
from 13D/G
|
5,462,015
|
$146,272,762 | — | 31 Dec 2025 | |
| VANGUARD GROUP INC |
13F
|
Company |
5.6%
|
2,608,158
|
$69,846,471 | — | 31 Dec 2025 | |
| Mary Z. Luo |
3/4/5
|
COO,Chief Scientist & Chairman, Director, 10%+ Owner |
—
class O/S missing
|
1,109,416
|
$63,239,930 | — | 10 Jan 2024 | |
| TD ASSET MANAGEMENT INC |
13F
|
Company |
4.2%
|
1,963,052
|
$52,570,533 | — | 31 Dec 2025 | |
| DIMENSIONAL FUND ADVISORS LP |
13F
|
Company |
3.9%
|
1,799,685
|
$48,196,126 | — | 31 Dec 2025 | |
| STATE STREET CORP |
13F
|
Company |
3.3%
|
1,531,786
|
$41,021,229 | — | 31 Dec 2025 | |
| FULLER & THALER ASSET MANAGEMENT, INC. |
13F
|
Company |
3%
|
1,394,463
|
$37,343,725 | — | 31 Dec 2025 | |
| MARSHALL WACE, LLP |
13F
|
Company |
2.7%
|
1,237,284
|
$33,134,466 | — | 31 Dec 2025 | |
| Epoch Investment Partners, Inc. |
13F
|
Company |
2.4%
|
1,126,585
|
$30,169,946 | — | 31 Dec 2025 | |
| Boston Trust Walden Corp |
13F
|
Company |
2.3%
|
1,087,266
|
$29,116,984 | — | 31 Dec 2025 | |
| GEODE CAPITAL MANAGEMENT, LLC |
13F
|
Company |
1.9%
|
886,825
|
$23,753,330 | — | 31 Dec 2025 | |
| AMERICAN CENTURY COMPANIES INC |
13F
|
Company |
1.4%
|
665,336
|
$17,817,698 | — | 31 Dec 2025 | |
| MORGAN STANLEY |
13F
|
Company |
1.3%
|
591,631
|
$15,843,918 | — | 31 Dec 2025 | |
| Richard Koo |
3/4/5
|
Director |
—
mixed-class rows
|
286,471
mixed-class rows
|
$15,350,254 | — | 07 Jun 2021 | |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP |
13F
|
Company |
1.2%
|
559,426
|
$14,981,428 | — | 31 Dec 2025 | |
| D. E. Shaw & Co., Inc. |
13F
|
Company |
1.2%
|
557,066
|
$14,918,227 | — | 31 Dec 2025 | |
| GOLDMAN SACHS GROUP INC |
13F
|
Company |
1.2%
|
556,709
|
$14,908,667 | — | 31 Dec 2025 | |
| RENAISSANCE TECHNOLOGIES LLC |
13F
|
Company |
1.2%
|
544,700
|
$14,587,066 | — | 31 Dec 2025 | |
| Invesco Ltd. |
13F
|
Company |
1.1%
|
501,404
|
$13,427,600 | — | 31 Dec 2025 | |
| SYSTEMATIC FINANCIAL MANAGEMENT LP |
13F
|
Company |
0.94%
|
435,580
|
$11,664,862 | — | 31 Dec 2025 | |
| HOTCHKIS & WILEY CAPITAL MANAGEMENT LLC |
13F
|
Company |
0.87%
|
402,563
|
$10,780,637 | — | 31 Dec 2025 | |
| NORTHERN TRUST CORP |
13F
|
Company |
0.8%
|
371,391
|
$9,945,851 | — | 31 Dec 2025 | |
| ROYCE & ASSOCIATES LP |
13F
|
Company |
0.76%
|
352,297
|
$9,434,514 | — | 31 Dec 2025 | |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC |
13F
|
Company |
0.76%
|
350,707
|
$9,391,937 | — | 31 Dec 2025 | |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC |
13F
|
Company |
0.7%
|
323,549
|
$8,664,642 | — | 31 Dec 2025 | |
| Clark Capital Management Group, Inc. |
13F
|
Company |
0.68%
|
317,482
|
$8,502,168 | — | 31 Dec 2025 | |
| VICTORY CAPITAL MANAGEMENT INC |
13F
|
Company |
0.66%
|
305,161
|
$8,172,211 | — | 31 Dec 2025 | |
| MILLENNIUM MANAGEMENT LLC |
13F
|
Company |
0.63%
|
290,673
|
$7,784,223 | — | 31 Dec 2025 | |
| Bank of New York Mellon Corp |
13F
|
Company |
0.56%
|
259,061
|
$6,937,655 | — | 31 Dec 2025 | |
| UBS Group AG |
13F
|
Company |
0.55%
|
256,624
|
$6,872,391 | — | 31 Dec 2025 | |
| Bridge City Capital, LLC |
13F
|
Company |
0.51%
|
235,485
|
$6,306,288 | — | 31 Dec 2025 | |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC |
13F
|
Company |
0.5%
|
231,305
|
$6,194,348 | — | 31 Dec 2025 | |
| CITADEL ADVISORS LLC |
13F
|
Company |
0.49%
|
228,724
|
$6,125,229 | — | 31 Dec 2025 | |
| PRINCIPAL FINANCIAL GROUP INC |
13F
|
Company |
0.47%
|
217,974
|
$5,837,344 | — | 31 Dec 2025 | |
| JANE STREET GROUP, LLC |
13F
|
Company |
0.47%
|
217,537
|
$5,825,641 | — | 31 Dec 2025 | |
| DENALI ADVISORS LLC |
13F
|
Company |
0.46%
|
211,765
|
$5,671,067 | — | 31 Dec 2025 | |
| Pacer Advisors, Inc. |
13F
|
Company |
0.38%
|
177,744
|
$4,759,984 | — | 31 Dec 2025 | |
| Rong Zhou |
3/4/5
|
SENIOR EVP, PRODUCTION CENTER |
—
mixed-class rows
|
257,895
mixed-class rows
|
$4,676,915 | -$256,379 | 15 Mar 2026 | |
| William J. Peters |
3/4/5
|
CFO, EVP & TREASURER, Director |
—
mixed-class rows
|
296,134
mixed-class rows
|
$4,637,418 | — | 15 Mar 2026 | |
| Empowered Funds, LLC |
13F
|
Company |
0.36%
|
165,907
|
$4,442,989 | — | 31 Dec 2025 | |
| JPMORGAN CHASE & CO |
13F
|
Company |
0.34%
|
158,644
|
$4,248,486 | — | 31 Dec 2025 | |
| Howard Lee |
3/4/5
|
Director |
—
mixed-class rows
|
163,378
mixed-class rows
|
$3,952,895 | — | 02 Jun 2025 | |
| FIRST TRUST ADVISORS LP |
13F
|
Company |
0.3%
|
140,310
|
$3,757,501 | — | 31 Dec 2025 | |
| AMERIPRISE FINANCIAL INC |
13F
|
Company |
0.29%
|
133,715
|
$3,580,888 | — | 31 Dec 2025 | |
| LAM GROUP, INC. |
13F
|
Company |
0.28%
|
130,800
|
$3,502,824 | — | 31 Dec 2025 | |
| NORDEA INVESTMENT MANAGEMENT AB |
13F
|
Company |
0.28%
|
129,144
|
$3,459,768 | — | 31 Dec 2025 | |
| BANK OF AMERICA CORP /DE/ |
13F
|
Company |
0.28%
|
128,174
|
$3,432,501 | — | 31 Dec 2025 | |
| NEW YORK STATE COMMON RETIREMENT FUND |
13F
|
Company |
0.27%
|
125,968
|
$3,373,423 | — | 31 Dec 2025 | |
| ALGERT GLOBAL LLC |
13F
|
Company |
0.27%
|
125,130
|
$3,351,000 | — | 31 Dec 2025 |
Institutional Holders of Amphastar Pharmaceuticals, Inc. - Common Stock (AMPH) as of Q1 2026
As of 31 Mar 2026,
Amphastar Pharmaceuticals, Inc. - Common Stock (AMPH) was held by
211 institutional
shareholders
that filed Form 13F with the SEC.
Together, they reported ownership of
32,080,880 shares.
The largest 10 holders included
BlackRock, Inc., DIMENSIONAL FUND ADVISORS LP, STATE STREET CORP, VANGUARD CAPITAL MANAGEMENT LLC, TD Asset Management Inc, FULLER & THALER ASSET MANAGEMENT, INC., MARSHALL WACE, LLP, AMERICAN CENTURY COMPANIES INC, GEODE CAPITAL MANAGEMENT, LLC, and Boston Trust Walden Corp.
This page lists
211
institutional shareholders reporting positions in this security
for the Q1 2026 filing period.
| Investor | Option | Weight % | Change % | Value $ | * Price | Shares | Share Change | Activity | Report Period |
|---|
Compare Q1 2026 vs Q4 2025 Across Filers
Q4 2025 holders
232
Q1 2026 holders
211
Holder diff
-21
| Investor | Q4 2025 Shares | Q1 2026 Shares | Share Diff | Share Chg % | Q4 2025 Value $ | Q1 2026 Value $ | Value Diff $ | Value Chg % |
|---|
Trend: ostatnie 8 kwartałów (+ wybrane okresy porównania).
Quarterly Holders Trend
Quarterly Value Trend
Quarterly Shares Trend
* Reported Price is the price of the security as of the portfolio date. This value is significant in that it is the last known price at which the security was still held.
An asterisk sign (*) next to the price indicates that the price is likely invalid.
An asterisk sign (*) next to the price indicates that the price is likely invalid.