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Amphastar Pharmaceuticals, Inc. (AMPH)

Amphastar Pharmaceuticals, Inc. (AMPH) Insider Trading

Directors, officers and holders of more than 10% of AMPH report their trades in its stock on SEC Form 4, within two business days. Each row below is one Form 4 transaction line. The one-letter code says what kind of transaction it was: only P (purchase) and S (sale) are open-market or private trades; awards, option exercises, tax withholding and gifts carry other codes.

Recent Form 4 transactions

The 50 most recent of 163 transactions on file: 0 with code P, 5 with code S and 45 with other codes.

DateInsiderCodeShares
Sep 21, 2026PETERS WILLIAM JS Sale4,139
Sep 16, 2026Zhou RongM Exercise10,000
Sep 16, 2026Zhou RongM Exercise10,000
Sep 16, 2026Zhou RongS Sale10,000
Sep 2, 2026Zhou RongS Sale3,187
Aug 11, 2026PRINS RICHARD KS Sale7,973
Aug 7, 2026PETERS WILLIAM JM Exercise5,053
Aug 7, 2026PETERS WILLIAM JM Exercise5,053
Aug 7, 2026PETERS WILLIAM JS Sale8,180
Jul 9, 2026Pierce Anthony TA Award16,646
Jul 9, 2026Pierce Anthony TA Award7,886
Jun 2, 2026Lee HowardF Tax Payment769
Jun 1, 2026Lee HowardA Award17,365
Jun 1, 2026Gaugh David RussellA Award17,365
Jun 1, 2026Lee HowardA Award8,143
Jun 1, 2026ZASLOFF MICHAEL AA Award8,143
Jun 1, 2026Gaugh David RussellA Award8,143
Jun 1, 2026Deflin GayleA Award8,143
Jun 1, 2026Gerst Diane G.A Award17,365
Jun 1, 2026ZASLOFF MICHAEL AA Award17,365
Jun 1, 2026Gerst Diane G.A Award8,143
Jun 1, 2026Deflin GayleA Award17,365
Jun 1, 2026PRINS RICHARD KA Award17,365
Jun 1, 2026PRINS RICHARD KA Award8,143
Mar 15, 2026Zhou RongF Tax Payment1,225
Mar 15, 2026PETERS WILLIAM JF Tax Payment1,973
Mar 15, 2026Zhang Jack Y.F Tax Payment9,784
Mar 15, 2026Liawatidewi YakobF Tax Payment1,033
Mar 15, 2026Zhang Jack Y.F Tax Payment2,908
Mar 10, 2026Zhang Jack Y.F Tax Payment4,395
Mar 10, 2026Zhang Jack Y.F Tax Payment14,785
Mar 10, 2026Liawatidewi YakobF Tax Payment1,870
Mar 10, 2026Zhou RongF Tax Payment2,215
Mar 10, 2026PETERS WILLIAM JF Tax Payment3,297
Mar 9, 2026Zhang Jack Y.A Award180,504
Mar 9, 2026PETERS WILLIAM JA Award121,071
Mar 9, 2026Zhou RongA Award81,341
Mar 9, 2026Liawatidewi YakobA Award35,450
Mar 9, 2026Zhou RongA Award39,432
Mar 9, 2026Liawatidewi YakobA Award73,126
Mar 9, 2026PETERS WILLIAM JA Award58,693
Mar 9, 2026Zhang Jack Y.A Award372,338
Mar 9, 2026Zhang Jack Y.A Award149,472
Mar 9, 2026Zhang Jack Y.A Award72,462
Mar 6, 2026Zhang Jack Y.F Tax Payment3,077
Mar 6, 2026Zhang Jack Y.F Tax Payment7,773
Mar 6, 2026Zhou RongF Tax Payment1,357
Mar 6, 2026Liawatidewi YakobF Tax Payment1,144
Mar 6, 2026PETERS WILLIAM JF Tax Payment2,146
Mar 4, 2026PETERS WILLIAM JF Tax Payment1,744

The full Form 4 history is on the AMPH company page (Insider Trades card, View all).

Questions about this data

Which insider transactions are open-market trades?

Code P (open market or private purchase) and code S (open market or private sale). Code F is shares withheld to pay tax on vesting stock, A is an award from the company, M and X are option exercises and G is a gift. None of those is the insider choosing to buy or sell in the market.

How quickly are insider trades reported?

A Form 4 is due before the end of the second business day after the trade. The date shown is the transaction date from the form.

Who has to file Form 4?

Officers, directors and beneficial owners of more than 10% of a class of the company’s registered equity, under Section 16 of the Securities Exchange Act.

Look up any code in the Form 4 transaction code reference, or read Form 4 codes explained.