Amphastar Pharmaceuticals, Inc. (AMPH) Institutional Ownership

Institutions by Trading Activity

Ownership Statistics

47,677,000Shares Outstanding

35,657,677Shares held by institutions

$615,986,370Value of institutional holdings

74.79%Institutional ownership %

9.53%Shares Changed QoQ

229No. of institutional investors

Shares Owned by Institutions

Shares Purchased/Sold by Institutions

Ownership Summary

Amphastar Pharmaceuticals, Inc. (NASDAQ:AMPH) has 229 institutional investors that have filed 13F reports for the period ending December 2025.

These investors collectively held 73.6% of Amphastar Pharmaceuticals's outstanding shares in December 2025, up from 69.4% in September 2025.
Their total shares held in AMPH increased 8.23% from the prior quarter, while the number of investors in Amphastar Pharmaceuticals decreased 11.92% year over year.
During the quarter, 116 of these 229 funds increased positions in AMPH, 85 reduced exposure, and 28 held steady.
Altogether, these fund groups held 35.08Mn shares in AMPH by December 2025, up by 2.67Mn shares quarter on quarter, and up 676.05K shares year over year.
As of December 31, 2025, Boston Trust Walden Corp held the largest stake in Amphastar Pharmaceuticals with 944.79K shares, accounting for 1.98% of total shares outstanding.
The largest buyers of Amphastar Pharmaceuticals for the quarter ending December 2025 were EXCHANGE TRADED CONCEPTS, LLC (73.0K), Robeco Institutional Asset Management B.V. (66.41K), Blue Trust, Inc. (367), Bank of New Hampshire (206), Capital Advisors, Ltd. LLC (159).
Leading sellers of Amphastar Pharmaceuticals shares for the quarter ending December 2025 were Boston Trust Walden Corp (142.48K), CX Institutional (61.15K), SG Americas Securities, LLC (60.71K), Sterling Capital Management LLC (6.22K), SummerHaven Investment Management, LLC (5.57K).
Per Business Quant data, the top 10 holders of Amphastar Pharmaceuticals for the quarter ending December 2025 are Boston Trust Walden Corp (944.79K), LAM GROUP, INC. (130.8K), EXCHANGE TRADED CONCEPTS, LLC (82.42K), Robeco Institutional Asset Management B.V. (66.41K), SG Americas Securities, LLC (32.81K), SummerHaven Investment Management, LLC (32.63K), State of Alaska, Department of Revenue (27.41K), Louisiana State Employees Retirement System (15.7K), Assenagon Asset Management S.A. (15.22K), Janney Montgomery Scott LLC (13.82K).

229 Institutional Holders

35,657,677 Total Shares Held

Rows:

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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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