Amphastar Pharmaceuticals, Inc. (AMPH) Institutional Ownership

Institutions by Trading Activity

Ownership Statistics

47,677,000Shares Outstanding

35,637,200Shares held by institutions

$755,865,012Value of institutional holdings

74.75%Institutional ownership %

9.47%Shares Changed QoQ

229No. of institutional investors

Shares Owned by Institutions

Shares Purchased/Sold by Institutions

Ownership Summary

Amphastar Pharmaceuticals, Inc. (NASDAQ:AMPH) appears in 229 institutional 13F filings for the quarter ending December 2025.

Collectively, these holders controlled 73.6% of Amphastar Pharmaceuticals's outstanding shares in December 2025, up from 69.4% in September 2025.
They increased total shares held in Amphastar Pharmaceuticals by 8.23% from the prior quarter, while the number of investors in AMPH decreased 11.92% year over year.
Among the 229 funds, 116 bought more Amphastar Pharmaceuticals shares, 85 sold down, and 28 held their ground.
Institutional investors collectively held 35.08Mn shares in Amphastar Pharmaceuticals as of December 2025, up by 2.67Mn shares quarter on quarter, and up 676.05K shares year over year.
BlackRock, Inc. holds the largest position in AMPH at 5.46Mn shares as of December 31, 2025, or 11.46% of shares outstanding.
The biggest buyers of Amphastar Pharmaceuticals for the quarter ending December 2025 included FULLER & THALER ASSET MANAGEMENT, INC. (1.43Mn), Goldman Sachs Group Inc (872.19K), AMERICAN CENTURY COMPANIES INC (376.75K), MARSHALL WACE, LLP (363.22K), Empowered Funds, LLC (182.02K).
The biggest sellers of Amphastar Pharmaceuticals for the quarter ending December 2025 included MILLENNIUM MANAGEMENT LLC (407.09K), Jpmorgan Chase & Co (347.82K), ALGERT GLOBAL LLC (267.77K), Barclays Plc (132.12K), Qube Research & Technologies Ltd (129.77K).
Amphastar Pharmaceuticals's 10 largest shareholders as of December 2025 include BlackRock, Inc. (5.46Mn), FULLER & THALER ASSET MANAGEMENT, INC. (2.79Mn), VANGUARD GROUP INC (2.61Mn), TD ASSET MANAGEMENT INC (1.96Mn), DIMENSIONAL FUND ADVISORS LP (1.8Mn), State Street Corp (1.53Mn), MARSHALL WACE, LLP (1.24Mn), Epoch Investment Partners, Inc. (1.13Mn), Goldman Sachs Group Inc (1.11Mn), Boston Trust Walden Corp (1.09Mn) per Business Quant data.

229 Institutional Holders

35,637,200 Total Shares Held

Rows:

Download Data

Owner Name	Date	Shares Held	Change (QoQ)	Change (%)	Value (USD)
BlackRock, Inc.	31 Dec, 2025	5,462,015	-23,042	-0.42%	$146,272,762.00
FULLER & THALER ASSET MANAGEMENT, INC.	31 Dec, 2025	2,788,926	1,434,999	105.99%	$74,687,450.00
VANGUARD GROUP INC	31 Dec, 2025	2,608,158	-22,882	-0.87%	$69,846,471.00
TD ASSET MANAGEMENT INC	31 Dec, 2025	1,963,052	31,160	1.61%	$52,570,533.00
DIMENSIONAL FUND ADVISORS LP	31 Dec, 2025	1,799,685	44,020	2.51%	$48,196,126.00
State Street Corp	31 Dec, 2025	1,531,786	31,044	2.07%	$41,021,229.00
MARSHALL WACE, LLP	31 Dec, 2025	1,237,284	363,216	41.55%	$33,134,466.00
Epoch Investment Partners, Inc.	31 Dec, 2025	1,126,585	-7,401	-0.65%	$30,169,946.00
Goldman Sachs Group Inc	31 Dec, 2025	1,113,418	872,190	361.56%	$29,817,334.00
Boston Trust Walden Corp	31 Dec, 2025	1,087,266	-85,841	-7.32%	$29,116,984.00
GEODE CAPITAL MANAGEMENT, LLC	31 Dec, 2025	886,825	-35,752	-3.88%	$23,753,330.00
AMERICAN CENTURY COMPANIES INC	31 Dec, 2025	665,336	376,751	130.55%	$17,817,698.00
Morgan Stanley	31 Dec, 2025	591,631	16,952	2.95%	$15,843,918.00
ARROWSTREET CAPITAL, LIMITED PARTNERSHIP	31 Dec, 2025	559,426	167,116	42.60%	$14,981,428.00
D. E. Shaw & Co., Inc.	31 Dec, 2025	557,066	39,844	7.70%	$14,918,227.00
RENAISSANCE TECHNOLOGIES LLC	31 Dec, 2025	544,700	-42,200	-7.19%	$14,587,066.00
Invesco Ltd.	31 Dec, 2025	501,404	111,811	28.70%	$13,427,600.00
SYSTEMATIC FINANCIAL MANAGEMENT LP	31 Dec, 2025	435,580	12,468	2.95%	$11,664,862.00
HOTCHKIS & WILEY CAPITAL MANAGEMENT LLC	31 Dec, 2025	402,563	76,380	23.42%	$10,780,637.00
Northern Trust Corp	31 Dec, 2025	371,391	-28,079	-7.03%	$9,945,851.00

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