Amphastar Pharmaceuticals, Inc. (AMPH) Institutional Ownership

Institutions by Trading Activity

Ownership Statistics

46,891,892Shares Outstanding

553,623Shares held by institutions

$15,750,574Value of institutional holdings

69.75%Institutional ownership %

3.76%Shares Changed QoQ

221No. of institutional investors

Shares Owned by Institutions

Shares Purchased/Sold by Institutions

Ownership Summary

Recent 13F filings as of December 2025 show that 221 institutional investors hold a position in Amphastar Pharmaceuticals, Inc. (NASDAQ:AMPH).

The percentage of Amphastar Pharmaceuticals owned by institutions changed from 69.9% in September 2025 to 69.7% in December 2025, marking a slight down trend.
The company experienced a 3.76% quarterly change in institutional shares held, alongside a decrease of 14.67% in total owners annually.
During the quarter, 113 institutions bought more Amphastar Pharmaceuticals shares, 81 sold shares, and 27 of the 221 total investors held their position steady.
Collectively, institutional investors increased their stake in Amphastar Pharmaceuticals to 32.71Mn shares as of December 2025, a change that is up by 1.19Mn shares quarter on quarter and down 599.11K shares year over year.
BlackRock, Inc. continues to be the largest institutional holder of Amphastar Pharmaceuticals as of December 31, 2025, with a position of 5.46Mn shares, representing 11.65% of the company's outstanding stock.
Among the most significant buyers of Amphastar Pharmaceuticals during December 2025 were AMERICAN CENTURY COMPANIES INC (376.75K), MARSHALL WACE, LLP (363.22K), GOLDMAN SACHS GROUP INC (315.48K), ARROWSTREET CAPITAL, LIMITED PARTNERSHIP (167.12K), BESSEMER GROUP INC (120.75K).
Leading sellers of Amphastar Pharmaceuticals stock in December 2025 included MILLENNIUM MANAGEMENT LLC (407.09K), ALGERT GLOBAL LLC (267.77K), Qube Research & Technologies Ltd (129.77K), BNP PARIBAS FINANCIAL MARKETS (101.13K), JPMORGAN CHASE & CO (94.59K).
The top 10 institutional holders of Amphastar Pharmaceuticals for the quarter ending December 2025 included BlackRock, Inc. (5.46Mn), VANGUARD GROUP INC (2.61Mn), TD ASSET MANAGEMENT INC (1.96Mn), DIMENSIONAL FUND ADVISORS LP (1.80Mn), STATE STREET CORP (1.53Mn), FULLER & THALER ASSET MANAGEMENT, INC. (1.39Mn), MARSHALL WACE, LLP (1.24Mn), Epoch Investment Partners, Inc. (1.13Mn), Boston Trust Walden Corp (1.09Mn), GEODE CAPITAL MANAGEMENT, LLC (886.83K).

221 Institutional Holders

553,623 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
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
FULLER & THALER ASSET MANAGEMENT, INC.	31 Dec, 2025	1,394,463	40,536	2.99%	$37,343,725.00
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
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
GOLDMAN SACHS GROUP INC	31 Dec, 2025	556,709	315,481	130.78%	$14,908,667.00
RENAISSANCE TECHNOLOGIES LLC	31 Dec, 2025	544,700	-42,200	-7.19%	$14,587,066.00
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
ROYCE & ASSOCIATES LP	31 Dec, 2025	352,297	-14,025	-3.83%	$9,434,514.00

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