Jack Y. Zhang owns 26.01% of Amphastar Pharmaceuticals
11,062,856 shares as of the March 15, 2026 filing, worth $286M at the latest close.
AMPH · $1.1B market cap · Founder-ledGet an email when Jack Y. Zhang’s stake moves.
Free.
The stake
26.01%
worth $286M at the latest close
Stake rank
#228
by dollar value of the stake
Last sale
1,013 days ago
Jan 10, 2024
Last buy
3,078 days ago
May 16, 2018 · $642,824
Jack Y. Zhang owns 26.01% of Amphastar Pharmaceuticals, Inc.: 11,062,856 of 42,537,944 shares, worth about $286M at the 2026-10-16 close. The stake has moved from 21.29% in 2016 to 26.01% on 2026-07-31, across 13 sales and 1 purchase that moved it since 2016. The last trade that moved it was a planned sale of $7.2M on 2024-01-10.
How the stake is held
as of the Mar 15, 2026 filing
SHARES
OF THE STAKE
COMMON STOCK · stated Mar 15, 2026 · Form 4 ↗
HELD DIRECTLY
2,990,052
27.0%
HELD INDIRECTLY · 2 VEHICLES
8,072,804
73.0%
Indirect holding
6,827,679
61.7%
Indirect, per the filing’s footnote
1,245,125
11.3%
THE STAKE
11,062,856
26.01%