Arrowstreet Capital
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Arrowstreet Capital’s Amphastar Pharmaceuticals AMPH Stock Holding History

Arrowstreet Capital’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 		$2.35M Sell
116,653
-208,638
-64% -$4.21M ﹤0.01% 1495
2026
Q1 		$6.37M Sell
325,291
-234,135
-42% -$5.73M ﹤0.01% 1087
2025
Q4 		$15M Buy
559,426
+167,116
+43% +$4.3M 0.01% 813
2025
Q3 		$10.5M Buy
392,310
+311,071
+383% +$8.03M 0.01% 943
2025
Q2 		$1.87M Buy
+81,239
New +$2.02M ﹤0.01% 1457
2024
Q2 		– Sell
-22,539
Closed -$990K – 1499
2024
Q1 		$990K Buy
+22,539
New +$1.16M ﹤0.01% 1318
2023
Q4 		– Sell
-28,230
Closed -$1.3M – 1397
2023
Q3 		$1.3M Sell
28,230
-869
-3% -$47.4K ﹤0.01% 933
2023
Q2 		$1.67M Sell
29,099
-45,175
-61% -$2M ﹤0.01% 872
2023
Q1 		$2.79M Sell
74,274
-91,766
-55% -$3.01M ﹤0.01% 839
2022
Q4 		$4.65M Sell
166,040
-35,025
-17% -$1.02M 0.01% 695
2022
Q3 		$5.65M Sell
201,065
-103,607
-34% -$3.38M 0.01% 629
2022
Q2 		$10.6M Sell
304,672
-86,913
-22% -$3.1M 0.02% 485
2022
Q1 		$14.1M Sell
391,585
-24,464
-6% -$694K 0.02% 467
2021
Q4 		$9.69M Buy
416,049
+217,577
+110% +$4.45M 0.01% 661
2021
Q3 		$3.77M Buy
198,472
+52,554
+36% +$1.03M ﹤0.01% 997
2021
Q2 		$2.94M Buy
145,918
+90,049
+161% +$1.7M ﹤0.01% 1231
2021
Q1 		$1.02M Buy
+55,869
New +$1.04M ﹤0.01% 1785
2020
Q1 		– Sell
-520,984
Closed -$10.1M – 1848
2019
Q4 		$10.1M Buy
520,984
+67,149
+15% +$1.29M 0.02% 609
2019
Q3 		$9M Buy
453,835
+287,533
+173% +$5.99M 0.02% 530
2019
Q2 		$3.51M Buy
166,302
+15,761
+10% +$329K 0.01% 747
2019
Q1 		$3.08M Buy
+150,541
New +$3.37M 0.01% 964
2018
Q3 		– Sell
-34,840
Closed -$532K – 1067
2018
Q2 		$532K Buy
+34,840
New +$609K ﹤0.01% 910
2016
Q2 		– Sell
-48,212
Closed -$579K – 1320
2016
Q1 		$579K Sell
48,212
-186,910
-79% -$2.2M ﹤0.01% 1093
2015
Q4 		$3.35M Buy
235,122
+76,572
+48% +$1.01M 0.02% 661
2015
Q3 		$1.85M Buy
+158,550
New +$2.38M 0.01% 765

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

Arrowstreet Capital's AMPH Position: Q2 2026 in Review

Arrowstreet Capital reduced its Amphastar Pharmaceuticals (AMPH) stake by 64% in Q2 2026, selling an estimated $4.21M and leaving 116,653 shares worth $2.35M. The position accounts for ﹤0.01% of the portfolio, ranked #1495.

Arrowstreet Capital first reported a position in AMPH in Q3 2015 and has held it in 25 quarters since. The position peaked at $15M in Q4 2025. 212 funds tracked by Wall St. Rank hold AMPH as of Q2 2026.

  • Arrowstreet Capital held 116,653 shares of Amphastar Pharmaceuticals worth $2.35M as of Q2 2026.
  • Arrowstreet Capital sold 208,638 Amphastar Pharmaceuticals shares in Q2 2026, an estimated $4.21M.
  • Amphastar Pharmaceuticals made up ﹤0.01% of Arrowstreet Capital's portfolio in Q2 2026, its #1495 holding.
  • Arrowstreet Capital first reported a position in Amphastar Pharmaceuticals in Q3 2015 and has held it in 25 quarters since.
  • Arrowstreet Capital's Amphastar Pharmaceuticals position peaked at $15M in Q4 2025.
  • 212 funds tracked by Wall St. Rank held Amphastar Pharmaceuticals as of Q2 2026.

Based on Arrowstreet Capital's 13F filing for Q2 2026, filed 13 Aug 2026.