PDT Partners’s Amphastar Pharmaceuticals AMPH Stock Holding History

PDT Partners’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	–	Sell	-11,441	Closed	-$224K	–	494
2026 Q1	$224K	Buy	+11,441	New	+$280K	0.01%	488
2025 Q4	–	Sell	-14,630	Closed	-$390K	–	553
2025 Q3	$390K	Hold	14,630	–	–	0.02%	477
2025 Q2	$336K	Buy	+14,630	New	+$363K	0.02%	582
2025 Q1	–	Sell	-90,484	Closed	-$3.36M	–	737
2024 Q4	$3.36M	Buy	90,484 +9,300	+11%	+$425K	0.3%	109
2024 Q3	$3.94M	Buy	81,184 +71,482	+737%	+$3.14M	0.35%	63
2024 Q2	$388K	Buy	+9,702	New	+$402K	0.04%	518
2022 Q3	–	Sell	-54,804	Closed	-$1.91M	–	830
2022 Q2	$1.91M	Buy	54,804 +20,415	+59%	+$729K	0.17%	184
2022 Q1	$1.24M	Buy	34,389 +930	+3%	+$26.4K	0.11%	307
2021 Q4	$779K	Buy	33,459 +5,922	+22%	+$121K	0.06%	426
2021 Q3	$523K	Buy	+27,537	New	+$539K	0.04%	468
2015 Q3	–	Sell	-20,650	Closed	-$363K	–	1248
2015 Q2	$363K	Buy	+20,650	New	+$322K	0.01%	1075

Other funds holding AMPH

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

Dimensional Fund Advisors Austin, Texas $552B AUM 44.19% 1-Year Est. Return

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

American Century Companies Kansas City, Missouri $226B AUM 44.75% 1-Year Est. Return

Marshall Wace London, United Kingdom $127B AUM 46.06% 1-Year Est. Return

Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return

Fuller & Thaler Asset Management San Mateo, California $36.7B AUM 74.15% 1-Year Est. Return

D.E. Shaw & Co New York $210B AUM 57.28% 1-Year Est. Return

Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

PDT Partners's AMPH Position: Q2 2026 in Review

PDT Partners sold out of Amphastar Pharmaceuticals (AMPH) in Q2 2026, closing a stake of 11,441 shares — an estimated $224K sold.

PDT Partners first reported a position in AMPH in Q2 2015 and held it in 11 quarters. The position peaked at $3.94M in Q3 2024. 211 funds tracked by Wall St. Rank hold AMPH as of Q2 2026.

PDT Partners reported no remaining Amphastar Pharmaceuticals position as of Q2 2026 after selling out during the quarter.
PDT Partners sold 11,441 Amphastar Pharmaceuticals shares in Q2 2026, an estimated $224K.
PDT Partners first reported a position in Amphastar Pharmaceuticals in Q2 2015 and held it in 11 quarters.
PDT Partners's Amphastar Pharmaceuticals position peaked at $3.94M in Q3 2024.
211 funds tracked by Wall St. Rank held Amphastar Pharmaceuticals as of Q2 2026.

Based on PDT Partners's 13F filing for Q2 2026, filed 14 Aug 2026.