Amphastar Pharmaceuticals Ownership | Who Owns Amphastar Pharmaceuticals?


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Amphastar Pharmaceuticals Ownership Summary


Amphastar Pharmaceuticals is owned by 11.87% institutional investors, 24.30% insiders, and 63.84% retail investors. Blackrock is the largest institutional shareholder, holding 12.33% of AMPH shares. iShares Core S&P Small-Cap ETF is the top mutual fund, with 4.86% of its assets in Amphastar Pharmaceuticals shares.

AMPH Ownership Benchmark


TypeName% Inst% Insiders% Retail
StockAmphastar Pharmaceuticals11.87%24.30%63.84%
SectorHealthcare Stocks 232.86%10.65%-143.51%
IndustrySpecialty & Generic Drug Manufacturers Stocks20.25%11.78%67.97%

Institutional Shareholders


Top Institutional Shareholders by Total Shares

HolderShares% HoldingValue
Blackrock5.94M12.33%$237.70M
Blackrock funding, inc. /de5.46M11.75%$146.27M
Vanguard group2.61M5.61%$69.85M
Dimensional fund advisors lp2.03M4.34%$39.73M
Td asset management1.54M3.30%$30.19M
State street1.50M3.20%$39.99M
Fuller & thaler asset management1.39M3.00%$37.34M
Epoch investment partners1.13M2.42%$30.22M
Boston trust walden944.79K2.02%$18.51M
Geode capital management886.83K1.91%$23.75M

Top Institutional Shareholders by % of Total Assets

HolderShares% AssetsValue
Bridge city capital235.49K1.85%$6.31M
Lam group130.80K1.41%$2.56M
Mesirow institutional investment management380.39K1.09%$14.12M
Denali advisors266.46K0.58%$5.22M
Illumine investment management28.08K0.42%$550.05K
Summerhaven investment management32.63K0.39%$639.28K
Systematic financial management lp435.58K0.28%$11.66M
Hussman strategic advisors63.00K0.27%$1.23M
Rice hall james & associates129.34K0.19%$3.45M
Bridgeway capital management312.34K0.18%$8.32M

Top Buyers

HolderShares% AssetsChange
Millennium management868.55K0.01%612.00K
Lsv asset management651.71K0.03%541.41K
Goldman sachs group556.71K0.00%315.48K
Clark capital management group283.67K0.05%283.67K
Algert global392.90K0.18%268.61K

Top Sellers

HolderShares% AssetsChange
Neuberger berman group---1.37M
Boston partners---423.07K
Td asset management1.54M0.02%-422.01K
Granite investment partners---375.78K
Boone capital management---316.56K

New Positions

HolderShares% AssetsChangeValue
Clark capital management group283.67K0.05%283.67K$7.56M
Vanguard fiduciary trust231.04K0.00%231.04K$4.53M
Rice hall james & associates129.34K0.19%129.34K$3.45M
Brandywine global investment management105.42K0.02%105.42K$2.82M
Robeco institutional asset management b.v.66.41K0.00%66.41K$1.30M

Sold Out

HolderChange
Sjs investment consulting-1.00
Financial gravity asset management-1.00
Caitong asset management-3.00
Jfs wealth advisors-3.00
Wealthtrak capital management-5.00

Institutional Ownership Trends


DateHoldingsChange %SharesChange %OwnershipChange %Increased PositionChange %Decreased PositionChange %
Dec 31, 202576-68.98%5,515,721-83.16%110.24%31-74.17%32-63.64%
Sep 30, 2025104-55.93%8,585,305-72.26%180.42%45-65.91%47-33.80%
Jun 30, 2025237-2.47%32,613,359-1.94%691.43%13214.78%70-25.53%
Mar 31, 20255-98.12%1,063,934-97.00%20.04%3-97.50%2-98.02%
Dec 31, 2024261-7.45%35,408,7620.08%721.38%116-18.31%1007.53%

Top Mutual Funds Shareholders


HolderShares% HoldingChange
iShares Core S&P Small-Cap ETF2.16M4.86%564.00
FullerThaler Behavioral Small-Cap Equity1.34M2.95%46.67K
FullerThaler Behavioral Sm-Cp Eq R61.34M2.95%46.67K
FullerThaler Beh Small-Cap Equity SMA1.34M2.95%-
Vanguard Total Stock Mkt Idx Inv1.11M2.49%-
Vanguard US Total Market Shares ETF1.14M2.40%1.24K
TD U.S. Capital Reinvestment I981.53K2.16%-51.47K
Avantis US Small Cap Value ETF874.86K1.96%-
iShares Russell 2000 ETF844.94K1.90%7.14K
TD Epoch U.S. Quality Capital Reinvestmt770.52K1.73%-211.00K

Recent Insider Transactions


DateNameRoleActivityValue
Dec 17, 2025Zhou Rong SENIOR EVP, PRODUCTION CENTERSell$256.38K
Dec 12, 2025Petersen Floyd F.-Sell$62.89K
Dec 11, 2025Petersen Floyd F.-Sell$44.62K
Nov 25, 2025PRINS RICHARD K-Sell$113.25K
Nov 13, 2025Petersen Floyd F.-Sell$441.84K

Insider Transactions Trends


DateBuySell
2026 Q1--
2025 Q4-7
2025 Q3-3
2025 Q2-3
2025 Q1-2

AMPH Ownership FAQ


Who Owns Amphastar Pharmaceuticals?

Amphastar Pharmaceuticals shareholders are primarily institutional investors at 11.87%, followed by 24.30% insiders and 63.83% retail investors. The average institutional ownership in Amphastar Pharmaceuticals's industry, Specialty & Generic Drug Manufacturers Stocks, is 20.25%, which Amphastar Pharmaceuticals falls below.

Who owns the most shares of Amphastar Pharmaceuticals?

Amphastar Pharmaceuticals’s largest shareholders are Blackrock (5.94M shares, 12.33%), Blackrock funding, inc. /de (5.46M shares, 11.75%), and Vanguard group (2.61M shares, 5.61%). Together, they hold 29.69% of Amphastar Pharmaceuticals’s total shares outstanding.

Does Blackrock own Amphastar Pharmaceuticals?

Yes, BlackRock owns 12.33% of Amphastar Pharmaceuticals, totaling 5.94M shares as of Jun 2024. This represents 0.01% of BlackRock's total assets, with a market value of 237.7M$. In the last quarter, BlackRock decreased its holdings by -137K shares, a -2.25% change.

Who is Amphastar Pharmaceuticals’s biggest shareholder by percentage of total assets invested?

Bridge city capital is Amphastar Pharmaceuticals’s biggest shareholder by percentage of total assets invested, with 1.85% of its assets in 235.48K Amphastar Pharmaceuticals shares, valued at 6.31M$.

Who is the top mutual fund holder of Amphastar Pharmaceuticals shares?

iShares Core S&P Small-Cap ETF is the top mutual fund holder of Amphastar Pharmaceuticals shares, with 4.86% of its total shares outstanding invested in 2.16M Amphastar Pharmaceuticals shares.

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