JY
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Jeff Yass’s Amphastar Pharmaceuticals AMPH Stock Holding History

Jeff Yass’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
Q2 		$226K Buy
+11,200
New +$226K ﹤0.01% 11687
2025
Q1 		– Sell
-14,300
Closed -$531K – 12397
2024
Q4 		$531K Sell
14,300
-18,100
-56% -$828K ﹤0.01% 8516
2024
Q3 		$1.57M Buy
32,400
+14,300
+79% +$628K ﹤0.01% 5795
2024
Q2 		$724K Sell
18,100
-23,600
-57% -$978K ﹤0.01% 7335
2024
Q1 		$1.83M Buy
41,700
+2,800
+7% +$145K ﹤0.01% 5542
2023
Q4 		$2.41M Buy
38,900
+23,800
+158% +$1.25M ﹤0.01% 4983
2023
Q3 		$694K Sell
15,100
-25,300
-63% -$1.38M ﹤0.01% 7464
2023
Q2 		$2.32M Sell
40,400
-12,100
-23% -$536K ﹤0.01% 4853
2023
Q1 		$1.97M Buy
52,500
+14,500
+38% +$475K ﹤0.01% 5186
2022
Q4 		$1.06M Sell
38,000
-9,500
-20% -$276K ﹤0.01% 6052
2022
Q3 		$1.33M Buy
47,500
+11,100
+30% +$362K ﹤0.01% 5880
2022
Q2 		$1.27M Buy
+36,400
New +$1.3M ﹤0.01% 5948
2020
Q4 		– Sell
-10,800
Closed -$203K – 10962
2020
Q3 		$203K Buy
+10,800
New +$217K ﹤0.01% 9423
2017
Q2 		– Sell
-19,700
Closed -$286K – 9129
2017
Q1 		$286K Buy
+19,700
New +$310K ﹤0.01% 7413
2016
Q4 		– Sell
-13,400
Closed -$254K – 9523
2016
Q3 		$254K Sell
13,400
-27,000
-67% -$490K ﹤0.01% 7201
2016
Q2 		$651K Buy
+40,400
New +$570K ﹤0.01% 5667
2016
Q1 		– Sell
-13,500
Closed -$192K – 8948
2015
Q4 		$192K Buy
+13,500
New +$178K ﹤0.01% 8462
2015
Q3 		– Sell
-15,200
Closed -$267K – 9588
2015
Q2 		$267K Buy
+15,200
New +$237K ﹤0.01% 8746

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
American Century Companies
American Century Companies Kansas City, Missouri $226B AUM 44.75% 1-Year Est. Return
Marshall Wace
Marshall Wace London, United Kingdom $127B AUM 46.06% 1-Year Est. Return
Geode Capital Management
Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return
Fuller & Thaler Asset Management
Fuller & Thaler Asset Management San Mateo, California $36.7B AUM 74.15% 1-Year Est. Return
D.E. Shaw & Co
D.E. Shaw & Co New York $210B AUM 57.28% 1-Year Est. Return
Vanguard Portfolio Management
Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

Jeff Yass's AMPH Position: Q2 2026 in Review

Jeff Yass increased its Amphastar Pharmaceuticals (AMPH) stake by 246% in Q2 2026, buying an estimated $725K and bringing the position to 50,565 shares worth $1.02M. The position accounts for ﹤0.01% of the portfolio, ranked #8146.

Jeff Yass first reported a position in AMPH in Q2 2015 and has held it in 29 quarters since. The position peaked at $2.05M in Q1 2025. 209 funds tracked by Wall St. Rank hold AMPH as of Q2 2026.

  • Jeff Yass held 50,565 shares of Amphastar Pharmaceuticals worth $1.02M as of Q2 2026.
  • Jeff Yass bought 35,964 Amphastar Pharmaceuticals shares in Q2 2026, an estimated $725K.
  • Amphastar Pharmaceuticals made up ﹤0.01% of Jeff Yass's portfolio in Q2 2026, its #8146 holding.
  • Jeff Yass first reported a position in Amphastar Pharmaceuticals in Q2 2015 and has held it in 29 quarters since.
  • Jeff Yass's Amphastar Pharmaceuticals position peaked at $2.05M in Q1 2025.
  • 209 funds tracked by Wall St. Rank held Amphastar Pharmaceuticals as of Q2 2026.

Based on Susquehanna International Group's 13F filing for Q2 2026, filed 14 Aug 2026.