AMPH Amphastar Pharmaceuticals Inc.

NASDAQ
$23.78

Amphastar Pharmaceuticals Inc. (AMPH) Institutional Ownership

What the institutions did with AMPH last quarter, from their 13F filings. Counting managers rather than shares is the point: a single index fund adding to a position tells you far less than four hundred separate managers all deciding to. Positions as reported for the quarter ended June 30, 2026.

Managers compared
240
filed both this quarter and last
Managers holding
208
-3 on the quarter
Buyers
93
29 opened new
Sellers
108
32 sold out entirely
Buyer share
46.3%
of managers who traded it
Breadth
-7.5
net buyers, as a share of those trading

Every manager below opens. Subscribers can see any firm's whole portfolio — every position, its weight, and what they bought, trimmed and exited last quarter.

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Ownership map

Each block is one manager, sized by shares held and colored by how much they moved the position last quarter. Green added, red cut, grey stood pat.

Cut Unchanged Added Color saturates at ±50%.

Largest holders

Manager Shares % of reported
BlackRock, Inc. 5.2M 18.4%
DIMENSIONAL FUND ADVISORS LP 2.3M 8.1%
STATE STREET CORP 1.6M 5.8%
VANGUARD CAPITAL MANAGEMENT LLC 1.5M 5.2%
AMERICAN CENTURY COMPANIES INC 1.2M 4.2%
MARSHALL WACE, LLP 1.1M 3.8%
GEODE CAPITAL MANAGEMENT, LLC 969.8K 3.4%
FULLER & THALER ASSET MANAGEMENT, INC. 949.2K 3.4%
D. E. Shaw & Co., Inc. 887.0K 3.1%
VANGUARD PORTFOLIO MANAGEMENT LLC 809.6K 2.9%
LSV ASSET MANAGEMENT 642.0K 2.3%
RENAISSANCE TECHNOLOGIES LLC 525.1K 1.9%
GOLDMAN SACHS GROUP INC 505.4K 1.8%
SYSTEMATIC FINANCIAL MANAGEMENT LP 437.4K 1.5%
MORGAN STANLEY 434.8K 1.5%
UBS Group AG 393.1K 1.4%
HRT FINANCIAL LP 387.5K 1.4%
DENALI ADVISORS LLC 376.0K 1.3%
NORTHERN TRUST CORP 371.0K 1.3%
Bridge City Capital, LLC 338.7K 1.2%
CHARLES SCHWAB INVESTMENT MANAGEMENT INC 310.2K 1.1%
BRIDGEWAY CAPITAL MANAGEMENT, LLC 299.0K 1.1%
ROYCE & ASSOCIATES LP 294.8K 1.0%
TWO SIGMA INVESTMENTS, LP 248.1K 0.9%
FIRST TRUST ADVISORS LP 247.0K 0.9%

Largest changes

Manager Action Previous Current Change
TD Asset Management Inc Sold Out 1.5M 0 -1.5M
Boston Trust Walden Corp Sold Out 944.8K 0 -944.8K
Epoch Investment Partners, Inc. Sold Out 898.9K 0 -898.9K
Invesco Ltd. Reduced 604.8K 158.1K -446.7K
FULLER & THALER ASSET MANAGEMENT, INC. Reduced 1.4M 949.2K -445.9K
MILLENNIUM MANAGEMENT LLC Reduced 371.4K 31.8K -339.6K
HRT FINANCIAL LP Increased 56.2K 387.5K +331.3K
DIMENSIONAL FUND ADVISORS LP Increased 2.0M 2.3M +277.2K
D. E. Shaw & Co., Inc. Increased 665.5K 887.0K +221.5K
ARROWSTREET CAPITAL, LIMITED PARTNERSHIP Reduced 325.3K 116.7K -208.6K
BlackRock, Inc. Reduced 5.4M 5.2M -196.4K
RICE HALL JAMES & ASSOCIATES, LLC Sold Out 187.3K 0 -187.3K
GOLDMAN SACHS GROUP INC Increased 329.4K 505.4K +176.0K
AMERICAN CENTURY COMPANIES INC Increased 1.0M 1.2M +159.1K
AQR CAPITAL MANAGEMENT LLC Increased 78.8K 208.7K +129.9K
VOLORIDGE INVESTMENT MANAGEMENT, LLC Reduced 171.2K 50.9K -120.3K
FRANKLIN RESOURCES INC Reduced 139.3K 25.0K -114.3K
ROYCE & ASSOCIATES LP Reduced 406.2K 294.8K -111.4K
TWO SIGMA INVESTMENTS, LP Increased 138.1K 248.1K +110.0K
DENALI ADVISORS LLC Increased 266.5K 376.0K +109.5K
BNP PARIBAS FINANCIAL MARKETS Reduced 156.1K 54.7K -101.4K
VICTORY CAPITAL MANAGEMENT INC Reduced 249.6K 149.6K -100.0K
FIRST TRUST ADVISORS LP Increased 150.6K 247.0K +96.4K
JANE STREET GROUP, LLC Increased 92.5K 178.7K +86.3K
ALGERT GLOBAL LLC Increased 62.4K 131.4K +69.0K
HUSSMAN STRATEGIC ADVISORS, INC. Sold Out 63.0K 0 -63.0K
VANGUARD CAPITAL MANAGEMENT LLC Reduced 1.5M 1.5M -61.7K
Jump Financial, LLC New 0 56.8K +56.8K
O'SHAUGHNESSY ASSET MANAGEMENT, LLC Increased 103.9K 159.4K +55.5K
Point72 Asset Management, L.P. New 0 55.0K +55.0K
Squarepoint Ops LLC Increased 28.3K 78.8K +50.5K
CITADEL ADVISORS LLC Reduced 65.5K 16.2K -49.3K
Trexquant Investment LP Sold Out 47.9K 0 -47.9K
JPMORGAN CHASE & CO Reduced 104.6K 57.6K -47.0K
XTX Topco Ltd Reduced 87.7K 46.8K -40.9K
MARSHALL WACE, LLP Increased 1.0M 1.1M +40.7K
HSBC HOLDINGS PLC Sold Out 38.0K 0 -38.0K
BANK OF AMERICA CORP /DE/ Reduced 174.3K 136.8K -37.5K
Vanguard Global Advisers, LLC Increased 50.2K 87.6K +37.5K
SUSQUEHANNA INTERNATIONAL GROUP, LLP Increased 14.6K 50.6K +36.0K
Creative Planning Increased 16.4K 51.4K +35.0K
Y-Intercept (Hong Kong) Ltd New 0 34.7K +34.7K
STATE STREET CORP Increased 1.6M 1.6M +34.6K
NEW YORK STATE COMMON RETIREMENT FUND Increased 148.7K 181.1K +32.4K
BRIDGEWAY CAPITAL MANAGEMENT, LLC Reduced 330.5K 299.0K -31.5K
Engineers Gate Manager LP New 0 30.2K +30.2K
Freestone Grove Partners LP Sold Out 29.9K 0 -29.9K
RENAISSANCE TECHNOLOGIES LLC Reduced 553.9K 525.1K -28.8K
FMR LLC Increased 1.3K 29.0K +27.7K
UBS Group AG Reduced 420.3K 393.1K -27.2K
INTECH INVESTMENT MANAGEMENT LLC Increased 24.2K 49.8K +25.6K
Campbell & CO Investment Adviser LLC New 0 23.2K +23.2K
Brevan Howard Capital Management LP Increased 11.6K 34.2K +22.6K
VANGUARD PORTFOLIO MANAGEMENT LLC Increased 787.8K 809.6K +21.8K
Quantinno Capital Management LP New 0 20.8K +20.8K
Round Rock Advisors LLC Sold Out 20.5K 0 -20.5K
Pacer Advisors, Inc. Reduced 261.5K 241.2K -20.3K
Janney Montgomery Scott LLC Increased 13.8K 33.8K +20.0K
Man Group plc Reduced 37.3K 17.3K -19.9K
CITIGROUP INC Increased 35.9K 55.8K +19.9K

13F filings are due 45 days after quarter end and cover long positions in U.S.-listed equities only, so this is a lagged and partial picture: shorts, bonds and foreign listings never appear. Options positions are excluded here rather than folded into the share counts. Political ownership is coming.