Amphastar Pharmaceuticals, Inc. - Common Stock (AMPH) Institutional Ownership

13F Institutional Holders and Ownership History from Q2 2014 to Q4 2025

Type / Class
Equity / Common Stock
Symbol
AMPH on Nasdaq
Shares outstanding
46,377,939
Price per share
$26.25
All holders as of 31 Dec 2025
Q4 2025
Total 13F shares
33,565,086
Total reported value
$898,832,896
% of total 13F portfolios
0%
Share change
+940,583
Value change
+$25,248,234
Number of holders
232
Price from insider filings
$26.25
Reported Shares, Excluding Options vs Price
Reported Value, Excluding Options
Total Investors

Significant Owners of Amphastar Pharmaceuticals, Inc. - Common Stock (AMPH) based on Schedule 13D/G filings

Filer Ownership Change % Holdings Value Net Change Nb Shares Change % Reporting Name Report Period
Zhang Jack Y. 25% $301,456,363 12,524,153 Jack Y. Zhang 31 Dec 2024
BlackRock, Inc. 12% $142,136,789 5,333,463 BlackRock, Inc. 30 Sep 2025

As of 31 Dec 2025, 232 institutional investors reported holding 33,565,086 shares of Amphastar Pharmaceuticals, Inc. - Common Stock (AMPH). This represents 72% of the company’s total 46,377,939 outstanding shares.

Top 25 Institutional Shareholders

The largest institutional shareholders of Amphastar Pharmaceuticals, Inc. - Common Stock (AMPH) together control 56% of the company’s outstanding shares — a level of ownership often associated with strong institutional conviction and long‑term capital commitment.

Institution Ownership % Shares Held Share Change % Portfolio % Holdings Value
BlackRock, Inc. 12% 5,462,015 -0.42% 0% $146,272,762
VANGUARD GROUP INC 5.6% 2,608,158 -0.87% 0% $69,846,471
TD Asset Management Inc 4.2% 1,963,052 +1.6% 0.04% $52,570,533
DIMENSIONAL FUND ADVISORS LP 3.9% 1,799,685 +2.5% 0.01% $48,196,126
STATE STREET CORP 3.3% 1,531,786 +2.1% 0% $41,021,229
FULLER & THALER ASSET MANAGEMENT, INC. 3% 1,394,463 +3% 0.13% $37,343,725
MARSHALL WACE, LLP 2.7% 1,237,284 +42% 0.03% $33,134,466
Epoch Investment Partners, Inc. 2.4% 1,126,585 -0.65% 0.17% $30,169,946
Boston Trust Walden Corp 2.3% 1,087,266 -7.3% 0.22% $29,116,984
GEODE CAPITAL MANAGEMENT, LLC 1.9% 886,825 -3.9% 0% $23,753,330
AMERICAN CENTURY COMPANIES INC 1.4% 665,336 +131% 0.01% $17,817,698
MORGAN STANLEY 1.3% 591,631 +2.9% 0% $15,843,918
ARROWSTREET CAPITAL, LIMITED PARTNERSHIP 1.2% 559,426 +43% 0.01% $14,981,428
D. E. Shaw & Co., Inc. 1.2% 557,066 +7.7% 0.01% $14,918,227
GOLDMAN SACHS GROUP INC 1.2% 556,709 +131% 0% $14,908,667
RENAISSANCE TECHNOLOGIES LLC 1.2% 544,700 -7.2% 0.02% $14,587,066
Invesco Ltd. 1.1% 501,404 +29% 0% $13,427,600
SYSTEMATIC FINANCIAL MANAGEMENT LP 0.94% 435,580 +2.9% 0.27% $11,664,862
HOTCHKIS & WILEY CAPITAL MANAGEMENT LLC 0.87% 402,563 +23% 0.03% $10,780,637
NORTHERN TRUST CORP 0.8% 371,391 -7% 0% $9,945,851
ROYCE & ASSOCIATES LP 0.76% 352,297 -3.8% 0.1% $9,434,514
CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.76% 350,707 -1.6% 0% $9,391,937
BRIDGEWAY CAPITAL MANAGEMENT, LLC 0.7% 323,549 +3.6% 0.18% $8,664,642
Clark Capital Management Group, Inc. 0.68% 317,482 +12% 0.05% $8,502,168
VICTORY CAPITAL MANAGEMENT INC 0.66% 305,161 +44% 0% $8,172,211

Institutional Holders of Amphastar Pharmaceuticals, Inc. - Common Stock (AMPH) across Reporting Periods

Period Reported Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2025 Q4 33,565,086 $898,832,896 +$25,248,234 $26.78 232
2025 Q3 32,747,166 $872,750,705 +$1,263,943 $26.65 240
2025 Q2 32,731,709 $751,532,890 -$21,672,562 $22.96 243
2025 Q1 33,249,489 $963,158,808 -$63,190,016 $28.99 240
2024 Q4 35,163,514 $1,305,816,189 -$16,188,647 $37.13 261
2024 Q3 35,330,537 $1,713,563,419 +$41,888,246 $48.53 276
2024 Q2 34,395,410 $1,376,025,520 +$31,905,251 $40.00 268
2024 Q1 33,566,615 $1,473,434,135 -$321,352 $43.91 271
2023 Q4 33,295,380 $2,059,042,180 +$87,201,045 $61.85 273
2023 Q3 32,003,084 $1,472,015,140 +$20,443,300 $45.99 253
2023 Q2 31,353,069 $1,801,848,806 +$73,791,648 $57.47 241
2023 Q1 30,206,509 $1,132,914,126 +$45,004,448 $37.50 216
2022 Q4 29,163,019 $817,271,726 -$23,406,379 $28.02 208
2022 Q3 29,873,966 $840,021,516 -$35,843,317 $28.10 196
2022 Q2 30,557,166 $1,062,910,134 +$40,970,389 $34.79 217
2022 Q1 29,830,020 $1,070,980,758 +$25,890,372 $35.90 201
2021 Q4 29,169,816 $678,795,680 +$19,582,653 $23.29 165
2021 Q3 27,926,297 $530,762,683 +$12,225,786 $19.01 136
2021 Q2 27,261,956 $549,556,724 +$25,712,540 $20.16 142
2021 Q1 26,031,138 $476,843,577 +$545,086 $18.32 129
2020 Q4 25,994,308 $522,683,040 -$2,775,804 $20.11 126
2020 Q3 26,220,579 $491,828,114 -$4,779,592 $18.75 131
2020 Q2 26,338,746 $591,056,212 +$55,460,558 $22.46 132
2020 Q1 23,920,591 $355,117,215 -$14,172,545 $14.84 105
2019 Q4 24,555,993 $473,689,883 +$9,587,777 $19.29 116
2019 Q3 24,085,264 $477,743,008 +$39,111,793 $19.83 130
2019 Q2 22,325,317 $471,212,995 +$11,702,564 $21.11 129
2019 Q1 22,418,206 $457,984,013 +$3,993,993 $20.43 133
2018 Q4 22,224,435 $442,228,625 +$31,389,222 $19.90 129
2018 Q3 20,634,989 $396,966,940 +$11,955,958 $19.24 104
2018 Q2 20,104,298 $306,846,558 -$10,112,452 $15.26 110
2018 Q1 20,667,512 $387,520,854 +$4,863,050 $18.75 114
2017 Q4 20,638,746 $396,981,826 +$6,676,577 $19.24 104
2017 Q3 20,292,672 $362,569,441 -$2,721,250 $17.87 100
2017 Q2 20,446,108 $365,150,134 +$4,539,252 $17.86 106
2017 Q1 20,427,180 $296,235,043 +$42,154,775 $14.50 114
2016 Q4 22,346,694 $411,905,913 +$7,350,529 $18.42 135
2016 Q3 22,197,017 $421,063,192 +$114,569,375 $18.97 134
2016 Q2 16,184,121 $261,086,844 +$32,114,465 $16.12 104
2016 Q1 14,259,461 $171,232,000 -$8,847,105 $12.00 93
2015 Q4 14,731,020 $209,636,387 +$12,973,432 $14.23 93
2015 Q3 13,587,192 $158,819,188 -$3,114,129 $11.69 91
2015 Q2 13,322,195 $234,151,768 +$48,772,625 $17.58 85
2015 Q1 10,590,488 $158,146,254 +$40,390,095 $14.96 57
2014 Q4 7,933,683 $92,124,442 +$5,403,296 $11.61 54
2014 Q3 7,242,472 $84,362,000 +$80,866,904 $11.64 44
2014 Q2 300,000 $3,003,000 +$3,003,000 $10.01 2