Janus Henderson Group
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Janus Henderson Group’s Amphastar Pharmaceuticals AMPH Stock Holding History

Janus Henderson Group’s Portfolio AMPH Stock Details AMPH Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q1 		$331K Hold
16,868
– – ﹤0.01% 2175
2025
Q4 		$452K Hold
16,868
– – ﹤0.01% 2052
2025
Q3 		$449K Hold
16,868
– – ﹤0.01% 2049
2025
Q2 		$387K Sell
16,868
-107,534
-86% -$2.67M ﹤0.01% 2067
2025
Q1 		$3.54M Sell
124,402
-64,945
-34% -$2.07M ﹤0.01% 1016
2024
Q4 		$7.03M Buy
189,347
+42,302
+29% +$1.93M ﹤0.01% 805
2024
Q3 		$7.14M Sell
147,045
-9,219
-6% -$405K ﹤0.01% 770
2024
Q2 		$6.25M Sell
156,264
-2,934
-2% -$122K ﹤0.01% 768
2024
Q1 		$6.99M Sell
159,198
-6,000
-4% -$310K ﹤0.01% 774
2023
Q4 		$10.2M Buy
165,198
+52,618
+47% +$2.76M 0.01% 664
2023
Q3 		$5.18M Buy
112,580
+15,505
+16% +$846K ﹤0.01% 806
2023
Q2 		$5.58M Sell
97,075
-6,866
-7% -$304K ﹤0.01% 837
2023
Q1 		$3.9M Buy
103,941
+96,226
+1,247% +$3.15M ﹤0.01% 956
2022
Q4 		$216K Buy
+7,715
New +$224K ﹤0.01% 2153
2022
Q3 		– Sell
-7,767
Closed -$270K – 2189
2022
Q2 		$270K Sell
7,767
-355,737
-98% -$12.7M ﹤0.01% 2143
2022
Q1 		$13M Sell
363,504
-609,689
-63% -$17.3M 0.01% 840
2021
Q4 		$22.7M Buy
973,193
+2,642
+0.3% +$54K 0.01% 756
2021
Q3 		$18.4M Buy
970,551
+415,515
+75% +$8.14M 0.01% 814
2021
Q2 		$11.2M Buy
+555,036
New +$10.5M ﹤0.01% 918

Other funds holding AMPH

BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
Dimensional Fund Advisors
Dimensional Fund Advisors Austin, Texas $552B AUM 44.19% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return
Vanguard Capital Management
Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM
TD Asset Management
TD Asset Management Toronto, Ontario, Canada $115B AUM 41.58% 1-Year Est. Return
Fuller & Thaler Asset Management
Fuller & Thaler Asset Management San Mateo, California $36.7B AUM 74.15% 1-Year Est. Return
Marshall Wace
Marshall Wace London, United Kingdom $127B AUM 46.06% 1-Year Est. Return
American Century Companies
American Century Companies Kansas City, Missouri $226B AUM 44.75% 1-Year Est. Return
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return
BTW
Boston Trust Walden Boston, Massachusetts $13.1B AUM 24.63% 1-Year Est. Return

Janus Henderson Group's AMPH Position: Q1 2026 in Review

Janus Henderson Group held its Amphastar Pharmaceuticals (AMPH) position steady in Q1 2026 at 16,868 shares worth $331K. The position accounts for ﹤0.01% of the portfolio, ranked #2175.

Janus Henderson Group first reported a position in AMPH in Q2 2021 and has held it in 19 quarters since. The position peaked at $22.7M in Q4 2021. 215 funds tracked by Wall St. Rank hold AMPH as of Q1 2026.

  • Janus Henderson Group held 16,868 shares of Amphastar Pharmaceuticals worth $331K as of Q1 2026.
  • Janus Henderson Group left its Amphastar Pharmaceuticals share count unchanged in Q1 2026.
  • Amphastar Pharmaceuticals made up ﹤0.01% of Janus Henderson Group's portfolio in Q1 2026, its #2175 holding.
  • Janus Henderson Group first reported a position in Amphastar Pharmaceuticals in Q2 2021 and has held it in 19 quarters since.
  • Janus Henderson Group's Amphastar Pharmaceuticals position peaked at $22.7M in Q4 2021.
  • 215 funds tracked by Wall St. Rank held Amphastar Pharmaceuticals as of Q1 2026.

Based on Janus Henderson Group's 13F filing for Q1 2026, filed 15 May 2026.