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Amphastar Pharmaceuticals

US · AMPH #3194 by market cap
25.54 -0.37 -1.43%
Live - 5344 symbols - heartbeat 224s ago · 2026-10-08 08:29
Pre-market 25.54 0.00%
After-hours 25.54 0.00%
Market cap
1.09B
P/B
1.41
EPS
2.03
Reader sentiment Are you bullish or bearish on AMPH?

Anonymous reader poll. Unscientific, not investment advice.

✦ Quant Ownership Signal how this is computed

Accumulating
  • The number of reporting institutions increased by 1 in the most recent period (2026/Q3).
  • Total institutional ownership rose 0.2 percentage points.

Institutional ownership

Held by institutions
84.13% +0.17pp
Institutions
266 +1
As of
2026/Q3 vs. prior period

Ownership vs. money flow

Diverging

Institutions added shares last reporting period, and the stock has seen net outflows in main-fund flow over the last 20 trading sessions - the two are pointing in different directions.

Institutional ownership changes are reported quarterly with a lag; fund-flow data is daily. Treat this as a directional cross-check, not a precise timing signal.

Holder types

Mutual Fund53.97%
Private Company17.94%
Individual/Insider10.36%
Hedge Fund8.05%
Public Company2.31%
Government Pension Fund1.17%
Family Office/Trust0.39%
Insurance Company0.24%
Other5.54%

Top holders as of 2026-03-31

Applied Physics & Chemistry Laboratories, Inc. 16.05% · 6.83M sh
BlackRock 12.28% · 5.22M sh
Yongfeng Zhang 6.28% · 2.67M sh
Dimensional Fund Advisors 5.42% · 2.31M sh
Vanguard Capital Management, LLC 4.01% · 1.71M sh
State Street Global Advisors 3.86% · 1.64M sh
American Century Investment Management 2.77% · 1.18M sh
Ziping Luo 2.62% · 1.11M sh
Marshall Wace LLP 2.51% · 1.07M sh
Geode Capital Management, LLC 2.28% · 969.84K sh

Bar length is relative to the largest holder shown here, not to 100% of the company.

Insiders

50 filings tracked · 23 buys · 27 sells

NameRoleStake
Applied Physics & Chemistry Laboratories, Inc. -- 16.05%
Yongfeng Zhang Co-founder, President, CEO, Chief Scientific Officer & Director 6.28%
Ziping Luo Chairman of the Board, Chief Scientist & COO 2.62%
Rong Zhou Senior Executive Vice President of Production 0.48%
Shiren S. Lee Independent Director 0.36%
William Peters CFO, Executive VP of Finance, Treasurer & Director 0.16%
Floyd Petersen Independent Director 0.16%
Jacob Liawatidewi Executive VP of Sales, Marketing & Corporate Administration Center, Corporate Secretary and Director 0.15%
Michael Zasloff Independent Director 0.06%
Richard Prins Lead Independent Director 0.05%

Insider transactions most recent Form 4 filings

DateNameRoleTypeSharesPrice
2026-09-20 William Peters CFO, Executive VP of Finance, Treasurer & Director Automatic Disposition -4,139 $25.00
2026-09-15 Rong Zhou Senior Executive Vice President of Production Derivative Exercise and Sale -10,000 $13.35–23.94
2026-09-01 Rong Zhou Senior Executive Vice President of Production Open Market Disposition -3,187 $23.63
2026-08-31 Rong Zhou Senior Executive Vice President of Production Intent to Sell (Form 144) -13,187 $22.00
2026-08-10 Richard Prins Lead Independent Director Open Market Disposition -7,973 $20.30
2026-08-06 William Peters CFO, Executive VP of Finance, Treasurer & Director Automatic Disposition -3,127 $22.48
2026-08-06 William Peters CFO, Executive VP of Finance, Treasurer & Director Derivative Exercise and Sale -5,053 $19.79–22.48
2026-07-08 Anthony Pierce Independent Director Other Acquisition +7,886 --
2026-07-08 Anthony Pierce Independent Director Other Derivative Acquisition +16,646 $19.02
2026-06-01 Shiren S. Lee Independent Director Sale to Issuer -769 $18.45
2026-05-31 Michael Zasloff Independent Director Other Acquisition +8,143 --
2026-05-31 Michael Zasloff Independent Director Other Derivative Acquisition +17,365 $18.42
2026-05-31 Richard Prins Lead Independent Director Other Acquisition +8,143 --
2026-05-31 Richard Prins Lead Independent Director Other Derivative Acquisition +17,365 $18.42
2026-05-31 Shiren S. Lee Independent Director Other Acquisition +8,143 --
2026-05-31 Shiren S. Lee Independent Director Other Derivative Acquisition +17,365 $18.42
2026-05-31 Gayle Deflin Independent Director Other Acquisition +8,143 --
2026-05-31 Gayle Deflin Independent Director Other Derivative Acquisition +17,365 $18.42
2026-05-31 David Gaugh Director Other Acquisition +8,143 --
2026-05-31 David Gaugh Director Other Derivative Acquisition +17,365 $18.42

Form 4 filings, most recent per company. "Other Derivative Acquisition" rows are mostly RSU/option vesting, not open-market buying - the Type column says which.

Quote time 2026-10-08 08:29:55 · For reference only, not investment advice and not tailored to your situation.