Amphastar Pharmaceuticals AMPH Institutional Ownership

NASDAQ AMPH

$25.92 -0.22 (-0.82%)

As of: Oct 20, 2026 · 12:38 PM EDT

Institutions by Trading Activity

209 Institutions

Increased 96 45.9%

Unchanged 39 18.7%

Reduced 74 35.4%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

64.81%

▼-5.91 pp QoQ

Shares Held by Institutions

28.29Mn

of 43.64Mn outstanding

▼-11.74% QoQ

Shares Outstanding

43.64Mn

15.36Mn held outside 13F filers

Institutional Investors

209

filed 13F for Jun 2026

▼-4 vs prior quarter

Net Shares Added (QoQ)

-3.76Mn

distributed since last quarter

Value of Holdings

$747.30Mn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Updated Oct 11, 2026

Amphastar Pharmaceuticals, Inc. (NASDAQ:AMPH) was reported as a holding by 209 institutional investors in 13F filings for the quarter ended June 30, 2026.

Collectively, these holders controlled 64.81% of Amphastar Pharmaceuticals' outstanding shares in Q2 2026, down from 70.71% in Q1 2026.
Total shares held in AMPH fell 11.74% from Q1 2026; the number of holders fell 12.92% from Q2 2025.
Of these 209 holders, 96 added to their positions, 74 reduced their stakes and 39 left their positions unchanged.
The aggregate institutional position in Amphastar Pharmaceuticals was 28.29Mn shares at the end of Q2 2026, down 3.76Mn from the prior quarter and down 3.43Mn from a year earlier.
As of June 30, 2026, the biggest holder of Amphastar Pharmaceuticals was BlackRock, Inc. with 5.22Mn shares, or 11.97% of shares outstanding.
Holders that added the most shares of Amphastar Pharmaceuticals in Q2 2026 were HRT Financial LP (+331.35K shares), Dimensional Fund Advisors LP (+277.16K shares), D. E. Shaw & Co., Inc. (+221.51K shares), Goldman Sachs Group Inc (+175.97K shares) and American Century Companies Inc (+159.09K shares).
The biggest cuts to AMPH positions during Q2 2026 came from Invesco Ltd. (-446.71K shares), Fuller & Thaler Asset Management, Inc. (-445.9K shares), Millennium Management LLC (-339.56K shares), Arrowstreet Capital, Limited Partnership (-208.64K shares) and BlackRock, Inc. (-196.41K shares).
Per Business Quant data, the 10 largest holders of Amphastar Pharmaceuticals at the end of Q2 2026 were BlackRock, Inc. (5.22Mn shares), Dimensional Fund Advisors LP (2.31Mn shares), State Street Corp (1.64Mn shares), Vanguard Capital Management LLC (1.48Mn shares), American Century Companies Inc (1.18Mn shares), Marshall Wace, LLP (1.07Mn shares), Geode Capital Management, LLC (969.84K shares), Fuller & Thaler Asset Management, Inc. (949.24K shares), D. E. Shaw & Co., Inc. (887.05K shares) and Vanguard Portfolio Management LLC (809.57K shares).

Form 13F Holdings

210 Institutional Holders

Report period 30 Jun, 2026

Total shares held 28.29Mn

Of outstanding 64.81%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	BlackRock, Inc.	0002012383	5,224,934	11.97%	▼196,409	-3.62%	$105.44Mn
2	DIMENSIONAL FUND ADVISORS LP	0000354204	2,305,107	5.28%	▲277,160	+13.67%	$46.52Mn
3	State Street Corp	0000093751	1,642,126	3.76%	▲34,611	+2.15%	$33.14Mn
4	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	1,481,952	3.40%	▼61,703	-4.00%	$29.91Mn
5	AMERICAN CENTURY COMPANIES INC	0000748054	1,176,626	2.70%	▲159,088	+15.63%	$23.74Mn
6	MARSHALL WACE, LLP	0001318757	1,066,322	2.44%	▲40,682	+3.97%	$21.52Mn
7	GEODE CAPITAL MANAGEMENT, LLC	0001214717	969,840	2.22%	▼6,810	-0.70%	$19.58Mn
8	FULLER & THALER ASSET MANAGEMENT, INC.	0001082327	949,238	2.17%	▼445,901	-31.96%	$19.16Mn
9	D. E. Shaw & Co., Inc.	0001009207	887,048	2.03%	▲221,506	+33.28%	$17.90Mn
10	VANGUARD PORTFOLIO MANAGEMENT LLC	0002100121	809,568	1.85%	▲21,752	+2.76%	$16.34Mn
11	LSV ASSET MANAGEMENT	0001050470	642,014	1.47%	▼9,700	-1.49%	$12.96K
12	RENAISSANCE TECHNOLOGIES LLC	0001037389	525,100	1.20%	▼28,800	-5.20%	$10.60Mn
13	Goldman Sachs Group Inc	0000886982	505,360	1.16%	▲175,972	+53.42%	$10.20Mn
14	SYSTEMATIC FINANCIAL MANAGEMENT LP	0001085936	437,384	1.00%	▼15,514	-3.43%	$8.83Mn
15	Morgan Stanley	0000895421	434,840	1.00%	▲14,503	+3.45%	$8.78Mn
16	UBS Group AG	0001610520	393,110	0.90%	▼27,153	-6.46%	$7.93Mn
17	HRT FINANCIAL LP	0001475597	387,530	0.89%	▲331,349	+589.79%	$7.82K
18	DENALI ADVISORS LLC	0001142941	375,965	0.86%	▲109,500	+41.09%	$7.59Mn
19	Northern Trust Corp	0000073124	370,991	0.85%	▼1,288	-0.35%	$7.49Mn
20	Bridge City Capital, LLC	0001713521	338,708	0.78%	▲3,603	+1.08%	$6.84Mn

Showing 1 to 20 of 210 holders