AMPH · Amphastar Pharmaceuticals, Inc.
Market Cap
$936.26M
Shares
42.54M
Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.
Holders: 209
Total Value: $571,885,733
Total Shares: 28,310,032
Showing 1–100
of 212 holdings by value
· page 1 of 3
Institutional Ownership Trend
26 quarters
Superinvestors Holding AMPH
All superinvestors →Holder Concentration
Across 209 13F filers · Δ vs Mar 31, 2026Top Holder
18.4%
+1.7 pts
Top 5
41.7%
+4.3 pts
Top 10
58.3%
+4.3 pts
HHI
578
Broadly held+83
Quarterly Activity
vs Mar 31, 2026
New
33
Increased
63
Decreased
76
Sold Out
39
Unchanged
37
Holder count:
-6
Institutional value:
-10.0%
Shares held:
-12.7%
Top Buyers
vs Mar 31, 2026| Institution | Added | Now Holds | Open |
|---|---|---|---|
| Large HRT FINANCIAL LP | +331,349 | 387,530 | |
| Mega DIMENSIONAL FUND ADVISORS LP | +277,160 | 2,305,107 | |
| Mega D. E. Shaw & Co., Inc. | +221,506 | 887,048 | |
| Mega GOLDMAN SACHS GROUP INC | +175,972 | 505,360 | |
| Mega AMERICAN CENTURY COMPANIES INC | +159,088 | 1,176,626 |
Top Sellers
vs Mar 31, 2026| Institution | Sold | Now Holds | Open |
|---|---|---|---|
| Mega Invesco Ltd. | −446,710 | 158,064 | |
| Large FULLER & THALER ASSET MANAGEMENT, INC. | −445,901 | 949,238 | |
| Mega MILLENNIUM MANAGEMENT LLC | −339,559 | 31,814 | |
| Mega ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | −208,638 | 116,653 | |
| Mega BlackRock, Inc. | −196,409 | 5,224,934 |
Top New Positions
vs Mar 31, 2026| Institution | Acquired | Value (USD) | Open |
|---|---|---|---|
| Mid Jump Financial, LLC | 56,781 | $1,145,840 | |
| Large Point72 Asset Management, L.P. | 54,964 | $1,109,173 | |
| Mid Y-Intercept (Hong Kong) Ltd | 34,704 | $700,326 | |
| Mid Engineers Gate Manager LP | 30,191 | $609,254 | |
| Mid Campbell & CO Investment Adviser LLC | 23,211 | $468,397 |
Top Sold-Out Positions
vs Mar 31, 2026| Institution | Previously Held | Last Value (USD) | Open |
|---|---|---|---|
| Mega TD Asset Management Inc | 1,541,044 | $30,189,051 | |
| Large Boston Trust Walden Corp | 944,789 | $18,508,415 | |
| Large Epoch Investment Partners, Inc. | 898,895 | $17,609,353 | |
| Mid RICE HALL JAMES & ASSOCIATES, LLC | 187,348 | $3,670,147 | |
| Small HUSSMAN STRATEGIC ADVISORS, INC. | 63,000 | $1,234,170 |
| Holder | Value (USD) | % of 13F | Shares | Type | Filed | Open |
|---|---|---|---|---|---|---|
| Mega BlackRock, Inc. | $105,439,161 | 18.44% | 5,224,934 | Shares | 2026-08-07 | |
| Mega DIMENSIONAL FUND ADVISORS LP | $46,517,057 | 8.13% | 2,305,107 | Shares | 2026-08-11 | |
| Mega STATE STREET CORP | $33,138,102 | 5.79% | 1,642,126 | Shares | 2026-08-07 | |
| Mega VANGUARD CAPITAL MANAGEMENT LLC | $29,905,791 | 5.23% | 1,481,952 | Shares | 2026-08-13 | |
| Mega AMERICAN CENTURY COMPANIES INC | $23,744,312 | 4.15% | 1,176,626 | Shares | 2026-08-12 | |
| Large MARSHALL WACE, LLP | $21,518,377 | 3.76% | 1,066,322 | Shares | 2026-08-13 | |
| Mega GEODE CAPITAL MANAGEMENT, LLC | $19,571,370 | 3.42% | 969,840 | Shares | 2026-08-12 | |
| Large FULLER & THALER ASSET MANAGEMENT, INC. | $19,155,622 | 3.35% | 949,238 | Shares | 2026-08-12 | |
| Mega D. E. Shaw & Co., Inc. | $17,900,628 | 3.13% | 887,048 | Shares | 2026-08-14 | |
| Mega VANGUARD PORTFOLIO MANAGEMENT LLC | $16,337,082 | 2.86% | 809,568 | Shares | 2026-08-13 | |
| Large LSV ASSET MANAGEMENT | $12,955,842 | 2.27% | 642,014 | Shares | 2026-08-06 | |
| Large RENAISSANCE TECHNOLOGIES LLC | $10,596,518 | 1.85% | 525,100 | Shares | 2026-08-13 | |
| Mega GOLDMAN SACHS GROUP INC | $10,198,163 | 1.78% | 505,360 | Shares | 2026-08-14 | |
| Mid SYSTEMATIC FINANCIAL MANAGEMENT LP | $8,826,408 | 1.54% | 437,384 | Shares | 2026-08-14 | |
| Mega MORGAN STANLEY | $8,775,068 | 1.53% | 434,840 | Shares | 2026-08-13 | |
| Mega UBS Group AG | $7,932,958 | 1.39% | 393,110 | Shares | 2026-08-13 | |
| Large HRT FINANCIAL LP | $7,820,355 | 1.37% | 387,530 | Shares | 2026-08-14 | |
| Small DENALI ADVISORS LLC | $7,586,973 | 1.33% | 375,965 | Shares | 2026-08-10 | |
| Mega NORTHERN TRUST CORP Bank | $7,486,595 | 1.31% | 370,991 | Shares | 2026-08-13 | |
| Small Bridge City Capital, LLC | $6,835,127 | 1.20% | 338,708 | Shares | 2026-08-11 | |
| Mega CHARLES SCHWAB INVESTMENT MANAGEMENT INC | $6,259,392 | 1.09% | 310,178 | Shares | 2026-08-14 | |
| Mid BRIDGEWAY CAPITAL MANAGEMENT, LLC | $6,032,891 | 1.05% | 298,954 | Shares | 2026-08-14 | |
| Large ROYCE & ASSOCIATES LP | $5,948,216 | 1.04% | 294,758 | Shares | 2026-08-14 | |
| Mega TWO SIGMA INVESTMENTS, LP | $5,006,960 | 0.88% | 248,115 | Shares | 2026-08-14 | |
| Mega FIRST TRUST ADVISORS LP | $4,983,471 | 0.87% | 246,951 | Shares | 2026-08-11 | |
| Large Pacer Advisors, Inc. | $4,867,032 | 0.85% | 241,181 | Shares | 2026-08-13 | |
| Mega Bank of New York Mellon Corp Bank | $4,688,679 | 0.82% | 232,343 | Shares | 2026-08-06 | |
| Mega VANGUARD FIDUCIARY TRUST CO Bank | $4,529,966 | 0.79% | 224,478 | Shares | 2026-08-13 | |
| Mega AQR CAPITAL MANAGEMENT LLC | $4,210,575 | 0.74% | 208,651 | Shares | 2026-08-14 | |
| Mega PRINCIPAL FINANCIAL GROUP INC | $4,121,764 | 0.72% | 204,250 | Shares | 2026-08-04 | |
| Large NEW YORK STATE COMMON RETIREMENT FUND Pension | $3,655,041 | 0.64% | 181,122 | Shares | 2026-07-29 | |
| Mega JANE STREET GROUP, LLC | $3,606,851 | 0.63% | 178,734 | Shares | 2026-08-14 | |
| Large Empowered Funds, LLC | $3,285,546 | 0.57% | 162,812 | Shares | 2026-08-17 | |
| Large O'SHAUGHNESSY ASSET MANAGEMENT, LLC | $3,217,236 | 0.56% | 159,427 | Shares | 2026-08-13 | |
| Mega Invesco Ltd. | $3,189,730 | 0.56% | 158,064 | Shares | 2026-08-14 | |
| Mega VICTORY CAPITAL MANAGEMENT INC | $3,019,170 | 0.53% | 149,612 | Shares | 2026-08-07 | |
| Large Universal- Beteiligungs- und Servicegesellschaft mbH | $2,813,132 | 0.49% | 139,402 | Shares | 2026-08-06 | |
| Mega BANK OF AMERICA CORP /DE/ Bank | $2,761,107 | 0.48% | 136,824 | Shares | 2026-08-14 | |
| Mid ALGERT GLOBAL LLC | $2,651,652 | 0.46% | 131,400 | Shares | 2026-08-13 | |
| Micro LAM GROUP, INC. | $2,639,544 | 0.46% | 130,800 | Shares | 2026-07-10 | |
| Mega NORDEA INVESTMENT MANAGEMENT AB | $2,561,467 | 0.45% | 126,931 | Shares | 2026-08-05 | |
| Large BESSEMER GROUP INC | $2,445,294 | 0.43% | 121,345 | Shares | 2026-08-12 | |
| Mega ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | $2,354,057 | 0.41% | 116,653 | Shares | 2026-08-13 | |
| Large Public Sector Pension Investment Board Pension | $2,353,956 | 0.41% | 116,648 | Shares | 2026-08-13 | |
| Mega Nuveen, LLC | $1,783,851 | 0.31% | 88,397 | Shares | 2026-08-11 | |
| Mega Vanguard Global Advisers, LLC | $1,768,555 | 0.31% | 87,639 | Shares | 2026-08-13 | |
| Large EXCHANGE TRADED CONCEPTS, LLC | $1,756,748 | 0.31% | 87,054 | Shares | 2026-08-11 | |
| Mega RHUMBLINE ADVISERS | $1,623,561 | 0.28% | 80,454 | Shares | 2026-08-12 | |
| Large Squarepoint Ops LLC | $1,590,083 | 0.28% | 78,795 | Shares | 2026-08-14 | |
| Mega Legal & General Group Plc | $1,579,709 | 0.28% | 78,281 | Shares | 2026-08-14 | |
| Large ASSETMARK, INC | $1,384,146 | 0.24% | 68,590 | Shares | 2026-07-30 | |
| Mega AMERIPRISE FINANCIAL INC | $1,377,163 | 0.24% | 68,244 | Shares | 2026-08-14 | |
| Large Robeco Institutional Asset Management B.V. | $1,340,093 | 0.23% | 66,407 | Shares | 2026-07-21 | |
| Mega Swiss National Bank Bank | $1,307,664 | 0.23% | 64,800 | Shares | 2026-08-11 | |
| Mega JPMORGAN CHASE & CO | $1,161,618 | 0.20% | 57,563 | Shares | 2026-08-12 | |
| Mid Jump Financial, LLC | $1,145,840 | 0.20% | 56,781 | Shares | 2026-08-13 | |
| Mega ALLIANCEBERNSTEIN L.P. | $1,138,757 | 0.20% | 56,430 | Shares | 2026-08-14 | |
| Mega WELLS FARGO & COMPANY/MN | $1,128,323 | 0.20% | 55,913 | Shares | 2026-08-14 | |
| Mega CITIGROUP INC | $1,125,619 | 0.20% | 55,779 | Shares | 2026-08-03 | |
| Large Point72 Asset Management, L.P. | $1,109,173 | 0.19% | 54,964 | Shares | 2026-08-14 | |
| Mega BNP PARIBAS ARBITRAGE, SA | $1,103,099 | 0.19% | 54,663 | Shares | 2026-08-13 | |
| Large Creative Planning | $1,038,139 | 0.18% | 51,444 | Shares | 2026-08-13 | |
| Mega PRICE T ROWE ASSOCIATES INC /MD/ | $1,031,258 | 0.18% | 51,103 | Shares | 2026-08-14 | |
| Large VOLORIDGE INVESTMENT MANAGEMENT, LLC | $1,027,404 | 0.18% | 50,912 | Shares | 2026-08-14 | |
| Mega SUSQUEHANNA INTERNATIONAL GROUP, LLP | $1,020,401 | 0.18% | 50,565 | Shares | 2026-08-14 | |
| Large INTECH INVESTMENT MANAGEMENT LLC | $1,005,751 | 0.18% | 49,839 | Shares | 2026-08-10 | |
| Mid SteelPeak Wealth, LLC | $982,443 | 0.17% | 48,684 | Shares | 2026-07-13 | |
| Mid XTX Topco Ltd | $944,585 | 0.17% | 46,808 | Shares | 2026-08-14 | |
| Mega UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC | $889,170 | 0.16% | 44,062 | Shares | 2026-08-13 | |
| Mid Polaris Capital Management, LLC | $872,421 | 0.15% | 43,232 | Shares | 2026-07-27 | |
| Mega CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM Pension | $729,527 | 0.13% | 36,151 | Shares | 2026-08-24 | |
| Mega DEUTSCHE BANK AG\ Bank | $712,495 | 0.12% | 35,307 | Shares | 2026-08-07 | |
| Large PRUDENTIAL FINANCIAL INC | $708,983 | 0.12% | 35,133 | Shares | 2026-08-12 | |
| Mid Y-Intercept (Hong Kong) Ltd | $700,326 | 0.12% | 34,704 | Shares | 2026-07-14 | |
| Large Vident Advisory, LLC | $690,579 | 0.12% | 34,221 | Shares | 2026-08-12 | |
| Mid Brevan Howard Capital Management LP | $690,176 | 0.12% | 34,201 | Shares | 2026-08-14 | |
| Large Janney Montgomery Scott LLC | $682,911 | 0.12% | 33,841 | Shares | 2026-08-05 | |
| Mid SEGALL BRYANT & HAMILL, LLC | $672,357 | 0.12% | 33,318 | Shares | 2026-08-12 | |
| Small SummerHaven Investment Management, LLC | $658,533 | 0.12% | 32,633 | Shares | 2026-07-21 | |
| Mega MILLENNIUM MANAGEMENT LLC | $642,006 | 0.11% | 31,814 | Shares | 2026-08-14 | |
| Mega SG Americas Securities, LLC Broker-Dealer | $639,887 | 0.11% | 31,709 | Shares | 2026-08-07 | |
| Mid Engineers Gate Manager LP | $609,254 | 0.11% | 30,191 | Shares | 2026-08-14 | |
| Small Illumine Investment Management, LLC | $594,180 | 0.10% | 0 | Shares | 2026-07-29 | |
| Mega FMR LLC | $584,371 | 0.10% | 28,958 | Shares | 2026-08-13 | |
| Large CANADA LIFE ASSURANCE Co Insurance | $540,561 | 0.09% | 26,787 | Shares | 2026-08-13 | |
| Mid State of Alaska, Department of Revenue | $533,417 | 0.09% | 26,433 | Shares | 2026-07-20 | |
| Small Advisor OS, LLC | $512,672 | 0.09% | 25,405 | Shares | 2026-08-05 | |
| Small ADVISORY RESEARCH INC | $511,300 | 0.09% | 25,337 | Shares | 2026-08-13 | |
| Mega BARCLAYS PLC | $508,878 | 0.09% | 25,217 | Shares | 2026-08-14 | |
| Mega FRANKLIN RESOURCES INC | $504,216 | 0.09% | 24,986 | Shares | 2026-08-13 | |
| Large Quadrature Capital Ltd | $492,957 | 0.09% | 24,428 | Shares | 2026-08-07 | |
| Mid Campbell & CO Investment Adviser LLC | $468,397 | 0.08% | 23,211 | Shares | 2026-08-03 | |
| Mega VANGUARD ASSET MANAGEMENT, Ltd | $465,189 | 0.08% | 23,052 | Shares | 2026-08-13 | |
| Large Thrivent Financial for Lutherans | $449,913 | 0.08% | 22,295 | Shares | 2026-08-14 | |
| Large NEW YORK STATE TEACHERS RETIREMENT SYSTEM Pension | $427,412 | 0.07% | 21,180 | Shares | 2026-07-23 | |
| Large Quantinno Capital Management LP | $420,288 | 0.07% | 20,827 | Shares | 2026-08-13 | |
| Large MetLife Investment Management, LLC | $418,956 | 0.07% | 20,761 | Shares | 2026-08-14 | |
| Mega RAYMOND JAMES FINANCIAL INC | $389,736 | 0.07% | 19,313 | Shares | 2026-08-14 | |
| Mega Russell Investments Group, Ltd. | $365,418 | 0.06% | 18,108 | Shares | 2026-08-06 | |
| Mid Illinois Municipal Retirement Fund Pension | $352,181 | 0.06% | 17,452 | Shares | 2026-08-12 |
Key facts
CIK
1297184
CUSIP
03209R103
13F (30d)
169 filings
167 filers
Visit website
Investor relations