Marshall Wace
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Marshall Wace’s Amphastar Pharmaceuticals AMPH Stock Holding History

Marshall Wace’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 		$21.5M Buy
1,066,322
+40,682
+4% +$821K 0.02% 698
2026
Q1 		$20.1M Sell
1,025,640
-211,644
-17% -$5.18M 0.02% 703
2025
Q4 		$33.1M Buy
1,237,284
+363,216
+42% +$9.36M 0.03% 464
2025
Q3 		$23.3M Buy
874,068
+25,383
+3% +$655K 0.02% 588
2025
Q2 		$19.5M Sell
848,685
-183,037
-18% -$4.54M 0.02% 595
2025
Q1 		$29.9M Buy
1,031,722
+423,016
+69% +$13.5M 0.04% 401
2024
Q4 		$22.6M Buy
608,706
+40,212
+7% +$1.84M 0.03% 500
2024
Q3 		$27.6M Buy
568,494
+341,367
+150% +$15M 0.03% 415
2024
Q2 		$9.09M Buy
+227,127
New +$9.41M 0.01% 775
2023
Q2 		– Sell
-64,209
Closed -$2.41M – 2431
2023
Q1 		$2.41M Buy
+64,209
New +$2.1M 0.01% 1356
2022
Q4 		– Sell
-31,638
Closed -$890K – 2909
2022
Q3 		$890K Buy
31,638
+3,197
+11% +$104K ﹤0.01% 2460
2022
Q2 		$989K Buy
28,441
+11,024
+63% +$393K ﹤0.01% 2442
2022
Q1 		$625K Buy
+17,417
New +$494K ﹤0.01% 2673
2020
Q3 		– Sell
-132,228
Closed -$2.97M – 1553
2020
Q2 		$2.97M Sell
132,228
-169,682
-56% -$3.11M 0.02% 642
2020
Q1 		$4.48M Buy
301,910
+7,846
+3% +$137K 0.04% 411
2019
Q4 		$5.67M Sell
294,064
-119,229
-29% -$2.29M 0.04% 486
2019
Q3 		$8.2M Buy
+413,293
New +$8.61M 0.06% 350

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
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
LSV Asset Management
LSV Asset Management Chicago, Illinois $55.1B AUM 45.38% 1-Year Est. Return

Marshall Wace's AMPH Position: Q2 2026 in Review

Marshall Wace increased its Amphastar Pharmaceuticals (AMPH) stake by 4% in Q2 2026, buying an estimated $821K and bringing the position to 1,066,322 shares worth $21.5M. The position accounts for 0.02% of the portfolio, ranked #698.

Marshall Wace first reported a position in AMPH in Q3 2019 and has held it in 17 quarters since. The position peaked at $33.1M in Q4 2025. 210 funds tracked by Wall St. Rank hold AMPH as of Q2 2026.

  • Marshall Wace held 1,066,322 shares of Amphastar Pharmaceuticals worth $21.5M as of Q2 2026.
  • Marshall Wace bought 40,682 Amphastar Pharmaceuticals shares in Q2 2026, an estimated $821K.
  • Amphastar Pharmaceuticals made up 0.02% of Marshall Wace's portfolio in Q2 2026, its #698 holding.
  • Marshall Wace first reported a position in Amphastar Pharmaceuticals in Q3 2019 and has held it in 17 quarters since.
  • Marshall Wace's Amphastar Pharmaceuticals position peaked at $33.1M in Q4 2025.
  • 210 funds tracked by Wall St. Rank held Amphastar Pharmaceuticals as of Q2 2026.

Based on Marshall Wace's 13F filing for Q2 2026, filed 13 Aug 2026.