Company · Ownership research

Amphastar Pharmaceuticals, Inc. AMPH

CIK 0001297184 · CUSIP 03209R103

Insider trading Initial holdings Institutional holders

Quarter-end disclosures, not live holdings.

Several CUSIPs are reported for this company; this page shows CUSIP 03209R103 (AMPH), not CUSIP 03209R903 (AMPH), CUSIP 03209R953 (AMPH), and does not merge CUSIPs.

This page lists the top 20 of 269 rows by value; the complete set is available through the API.

Some filings reported values in thousands; those figures were scaled ×1,000 to dollars.

Top 20 institutions

Weight means this stock's share of the manager's own portfolio.

By reported value

#	Manager	Value	Manager weight	Change vs prior	Source
01	BlackRock Inc. CIK 1364742 · View history	$237.70M 5,942,524 shares	0.01%	-136.52K(-2.20%)Reduced	SEC filing ↗ Aug 13, 2024	▾
02	VANGUARD GROUP INC CIK 102909 · View history	$106.91M 2,672,862 shares	0.00%	-61.18K(-2.20%)Reduced	SEC filing ↗ Aug 13, 2024	▾
03	FEDERATED HERMES, INC. CIK 1056288 · View history	$77.79M 1,944,800 shares	0.18%	-132.30K(-6.40%)Reduced	SEC filing ↗ Aug 8, 2024	▾
04	TD Asset Management Inc CIK 1056053 · View history	$67.66M 1,691,569 shares	0.06%	+680.98K(+67.40%)Added	SEC filing ↗ Aug 2, 2024	▾
05	NEUBERGER BERMAN GROUP LLC CIK 1465109 · Amended · View history	$64.90M 1,622,609 shares	0.05%	-37.21K(-2.20%)Reduced	SEC filing ↗ Nov 14, 2024	▾
06	STATE STREET CORP CIK 93751 · View history	$61.18M 1,529,536 shares	0.00%	+15.29K(+1.00%)Added	SEC filing ↗ Aug 14, 2024	▾
07	FULLER & THALER ASSET MANAGEMENT, INC. CIK 1082327 · View history	$50.91M 1,272,818 shares	0.22%	-1.36K(-0.10%)Reduced	SEC filing ↗ Aug 9, 2024	▾
08	Epoch Investment Partners, Inc. CIK 1305841 · View history	$43.15M 1,078,852 shares	0.20%	+280.39K(+35.10%)Added	SEC filing ↗ Aug 13, 2024	▾
09	DIMENSIONAL FUND ADVISORS LP CIK 354204 · View history	$42.81M 1,070,275 shares	0.01%	-113.56K(-9.60%)Reduced	SEC filing ↗ Aug 9, 2024	▾
10	GEODE CAPITAL MANAGEMENT, LLC CIK 1214717 · View history	$36.26M 906,348 shares	0.00%	+40.32K(+4.70%)Added	SEC filing ↗ Aug 9, 2024	▾
11	AMERICAN CENTURY COMPANIES INC CIK 748054 · View history	$29.62M 740,408 shares	0.02%	+121.76K(+19.70%)Added	SEC filing ↗ Aug 7, 2024	▾
12	MILLENNIUM MANAGEMENT LLC CIK 1273087 · View history	$29.55M 738,748 shares	0.02%	+338.65K(+84.60%)Added	SEC filing ↗ Aug 14, 2024	▾
13	MORGAN STANLEY CIK 895421 · Amended · View history	$24.41M 610,137 shares	0.00%	+51.10K(+9.10%)Added	SEC filing ↗ May 14, 2025	▾
14	PRICE T ROWE ASSOCIATES INC /MD/ CIK 80255 · View history	$23.36M 583,906 shares	0.00%	-638(-0.10%)Reduced	SEC filing ↗ Aug 14, 2024	▾
15	NORTHERN TRUST CORP CIK 73124 · View history	$22.56M 564,123 shares	0.00%	+3.34K(+0.60%)Added	SEC filing ↗ Aug 14, 2024	▾
16	RENAISSANCE TECHNOLOGIES LLC CIK 1037389 · View history	$21.51M 537,700 shares	0.04%	-61.40K(-10.20%)Reduced	SEC filing ↗ Aug 9, 2024	▾
17	BOONE CAPITAL MANAGEMENT LLC CIK 1882053 · View history	$19.80M 495,089 shares	5.17%	-111.60K(-18.40%)Reduced	SEC filing ↗ Aug 14, 2024	▾
18	BESSEMER GROUP INC CIK 1054074 · View history	$18.65M 466,228 shares	0.03%	+70.29K(+17.80%)Added	SEC filing ↗ Aug 13, 2024	▾
19	Invesco Ltd. CIK 914208 · View history	$18.04M 450,930 shares	0.00%	+47.89K(+11.90%)Added	SEC filing ↗ Aug 13, 2024	▾
20	Granite Investment Partners, LLC CIK 1542266 · View history	$15.90M 397,514 shares	0.66%	+44.74K(+12.70%)Added	SEC filing ↗ Aug 12, 2024	▾

Showing 20 / 269 institutions. The complete set is available through the API.

Coverage & totals by quarter

Reporting institutions

269

Cancelled or null records excluded

Disclosed shares

34,363,682

Not deduplicated across managers

Disclosed value

$1.37B

Not market cap or free float

Reporting institutions by quarter

Counts also change with data coverage and reporting entities; they do not measure net buying. Distinct managers with a live stock row in this CUSIP; totals may include overlapping filings and are not a share of the company.

Amphastar Pharmaceuticals, Inc. · Q2 2024

Explore all 269 reporting institutions.

This page includes 20 of 269 reporting institutions. Log in to look up the full history beyond 3 years, use advanced screening & filtering, download CSV, and get the complete set through the Akkru API.

Download CSV
Earlier quarters
Advanced screening & filtering
API & AI access

Already have an account?

＋ New accounts get free API credits to explore data beyond ownership filings.

For AI agents & developers

The initial HTML of this page carries its exact data as script#research-data (JSON): values, units, scope, preview limits and SEC sources. Read it directly, no script or API key needed; script#research-access says what needs an account. This page lists 20 of 269 reporting institutions; totals use the complete disclosed data.

Without an account: the last 3 years, with the row caps stated on the page. A free account opens all history on file on these pages and the CSV of what a page shows. Rows beyond the caps and bulk retrieval go through the authenticated API / MCP / CLI.

MCP  https://api.akkrudata.ai/mcp

akkru_institutional_holdings
{"action":"holders","cusip":"03209R103","quarter":"2024Q2","type":"positions","page_size":100}

Connect to MCP with OAuth and follow the returned pagination. Credits and usage limits depend on the account.

MCP endpoint: https://api.akkrudata.ai/mcp
API / MCP / CLI documentation: /documents
llms.txt: /llms.txt

Sources, coverage & how to read this data

Figures are as reported to the SEC and merged with later amendments where Akkru could match them. Preview limits apply to what is listed, not to the totals, which come from the complete reported data. Nothing is zero-filled: a missing quarter or month is shown as missing.