Stock Trading Canary

United States · SEC Form 4 · Snapshot date: 2026-10-18 · Built: 2026-10-18 · 中文

← United States · Coverage record

US · SEC FORM 4

Amphastar Pharmaceuticals, Inc.

AMPH · Nasdaq · CIK 0001297184 · Healthcare · Drug Manufacturers—Specialty & Generic

INSIDER SIGNAL

No active buy signal

0 qualifying P purchase groups
in the current 180-day scoring window

15 Form 4 transaction lines observed in the same window
5 sales · 10 option, withholding, award, gift or other lines

Last qualifying purchase2020-08-14 · Maris David · $20.3K

WHY NO ACTIVE SIGNAL?

Purchase activityNone
Recent buyingNone
Recent salesModerate
Buy signal statusInactive
Score anatomy

No score is calculated because there is no qualifying purchase in the active window. Unavailable inputs are not treated as zero or as a bearish signal.

ClusterNot calculated
Purchase sizeNot calculated
RoleNot calculated
RecencyNot calculated
ConvictionNot calculated

Why is there no score?

  • No qualifying open-market purchase supplies cluster, size, role, recency or conviction inputs.
  • Sales and other Form 4 activity remain visible as context and do not create a negative score.

Sales and other Form 4 activity are shown separately and do not create a negative buy signal. Absence of buying is not scored as bearish.

Insider activity timeline

Owner lanes show the latest 180 days. Symbol shape identifies the transaction type; sales remain context only.

AprMayJunJulAugSepOct
PETERS WILLIAM JCFO, EVP & TREASURER
○▼▼
Zhou RongSENIOR EVP, PRODUCTION CENTER
▼○▼
Lee HowardDirector
○○
PRINS RICHARD KDirector
○▼
ZASLOFF MICHAEL ADirector
○
Gerst Diane G.Director
○
● Purchase▼ Sale○ Other

Showing the six most active owners; 3 additional owner(s) remain in Form 4 evidence.

Purchase breadth, concentration & cluster buying

These modules activate when qualifying purchases enter the 180-day research window.

SIGNAL HISTORY

No recorded active-signal snapshot

Scores are archived only when the company qualifies for a published US buy-signal snapshot. Last qualifying purchase: 2020-08-14 · Maris David.

Recent Form 4 activity

0Purchases
11Sales
38Other Form 4 lines
33SEC filings · 365 days
BUYING0 qualifying P line(s) · 180 days
SELLING5 sale line(s) · context only
OTHER10 exercise / withholding / award / gift / other lines
10b5-1 / PLANNEDNot assessed

P is an open-market or private purchase. S is a sale. M, F, A and G usually describe exercises, tax withholding, awards and gifts. These categories remain visually separate.

Market context

Market context provides additional background on recent price performance and risk. It does not affect the Insider Signal.

Price performance

1M
+7.1%
3M
+29.7%
6M
+24.4%
12M
—

Volatility & liquidity

Volatility
51.9%
Beta
0.92
Avg daily value
USD 11.8M

Valuation

Market cap
USD 1.1B
P/E
15.0×

Fundamentals

Profit margin
13.6%
ROE
12.4%
Industry
Drug Manufacturers—Specialty & Generic

Market data

Price data up to: 2026-10-03 · Price source: OpenBB/yfinance · From SEC filings: Profit margin, ROE · Fiscal year ended: 2025-12-31 · From Yahoo Finance: Market cap, P/E · Status: PASS

Short interest

Short interest is external context reported to FINRA by broker-dealers. It does not affect the Insider Signal.

Shares short
4,405,038
Previous report
4,994,808
Avg daily volume
620,832
Days to cover
7.1

FINRA settlement date: 2026-09-30 · Captured 2026-10-12 · FINRA equity short interest ↗. A share count, published about a week after each of two settlement dates a month; not a percentage of shares outstanding.

Historical equity purchases

Qualifying code P transactions in the local Form 4 history, including purchases outside the current signal window.

Transaction dateReporting ownerTypeSecuritySharesAvg. priceApprox. valueSource
2020-08-14Maris DavidPurchase (P)Common Stock1,000USD 20.26USD 20,260SEC filing ↗

Form 4 evidence

49 transaction lines in the latest 365-day window; 614 in local history.

DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-09-21PETERS WILLIAM JSale (S)Common Stock4,139USD 25.00USD 103,475SEC filing ↗
2026-09-16Zhou RongSale (S)Common Stock10,000USD 23.94USD 239,400SEC filing ↗
2026-09-16Zhou RongOption exercise / conversion (M)Common Stock10,000USD 13.35USD 133,500SEC filing ↗
Show recent Form 4 evidence (30 grouped rows)
DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-09-21PETERS WILLIAM JSale (S)Common Stock4,139USD 25.00USD 103,475SEC filing ↗
2026-09-16Zhou RongSale (S)Common Stock10,000USD 23.94USD 239,400SEC filing ↗
2026-09-16Zhou RongOption exercise / conversion (M)Common Stock10,000USD 13.35USD 133,500SEC filing ↗
2026-09-02Zhou RongSale (S)Common Stock3,187USD 23.63USD 75,309SEC filing ↗
2026-08-11PRINS RICHARD KSale (S)Common Stock7,973USD 20.30USD 161,852SEC filing ↗
2026-08-07PETERS WILLIAM JSale (S)Common Stock8,180USD 22.48USD 183,886SEC filing ↗
2026-08-07PETERS WILLIAM JOption exercise / conversion (M)Common Stock5,053USD 19.79USD 99,999SEC filing ↗
2026-07-09Pierce Anthony TAward / grant (A)Common Stock7,886USD 0.00USD 0SEC filing ↗
2026-06-02Lee HowardTax withholding (F)Common Stock769USD 18.45USD 14,188SEC filing ↗
2026-06-01ZASLOFF MICHAEL AAward / grant (A)Common Stock8,143USD 0.00USD 0SEC filing ↗
2026-06-01PRINS RICHARD KAward / grant (A)Common Stock8,143USD 0.00USD 0SEC filing ↗
2026-06-01Lee HowardAward / grant (A)Common Stock8,143USD 0.00USD 0SEC filing ↗
2026-06-01Gerst Diane G.Award / grant (A)Common Stock8,143USD 0.00USD 0SEC filing ↗
2026-06-01Gaugh David RussellAward / grant (A)Common Stock8,143USD 0.00USD 0SEC filing ↗
2026-06-01Deflin GayleAward / grant (A)Common Stock8,143USD 0.00USD 0SEC filing ↗
2026-03-15Zhou RongTax withholding (F)Common Stock1,225USD 18.18USD 22,270SEC filing ↗
2026-03-15PETERS WILLIAM JTax withholding (F)Common Stock1,973USD 18.18USD 35,869SEC filing ↗
2026-03-15Luo Mary Z.; Zhang Jack Y.Tax withholding (F)Common Stock12,692USD 18.18USD 230,741SEC filing ↗
2026-03-15Liawatidewi YakobTax withholding (F)Common Stock1,033USD 18.18USD 18,780SEC filing ↗
2026-03-10Zhou RongTax withholding (F)Common Stock2,215USD 18.91USD 41,886SEC filing ↗
2026-03-10PETERS WILLIAM JTax withholding (F)Common Stock3,297USD 18.91USD 62,346SEC filing ↗
2026-03-10Luo Mary Z.; Zhang Jack Y.Tax withholding (F)Common Stock19,180USD 18.91USD 362,694SEC filing ↗
2026-03-10Liawatidewi YakobTax withholding (F)Common Stock1,870USD 18.91USD 35,362SEC filing ↗
2026-03-09Zhou RongAward / grant (A)Common Srock39,432USD 0.00USD 0SEC filing ↗
2026-03-09PETERS WILLIAM JAward / grant (A)Common Stock58,693USD 0.00USD 0SEC filing ↗
2026-03-09Luo Mary Z.; Zhang Jack Y.Award / grant (A)Common Stock252,966USD 0.00USD 0SEC filing ↗
2026-03-09Liawatidewi YakobAward / grant (A)Common Stock35,450USD 0.00USD 0SEC filing ↗
2026-03-06Zhou RongTax withholding (F)Common Stock1,357USD 19.34USD 26,244SEC filing ↗
2026-03-06PETERS WILLIAM JTax withholding (F)Common Stock2,146USD 19.34USD 41,504SEC filing ↗
2026-03-06Luo Mary Z.; Zhang Jack Y.Tax withholding (F)Common Stock10,850USD 19.34USD 209,839SEC filing ↗

Multiple price lines in one filing are grouped and share-weighted. Price and value are blank when a grouped filing line lacks price evidence.

Snapshot & identity

Snapshot date2026-10-18
Ranking versionUS-v1.2
Data qualityPASS ELIGIBLE · —
TickerAMPH
CIK0001297184
SectorHealthcare
IndustryDrug Manufacturers—Specialty & Generic Yahoo Finance
SEC SIC2834 Pharmaceutical Preparations
ExchangeNasdaq

Data coverage

Local Form 4 history614 transaction lines from 2020-01-02 to 2026-09-21
1 P purchase lines · 255 S sale lines · 358 other lines
SEC company submissionsOpen SEC filings ↗

Local ledger as of 2026-10-18. Mapping status is an audit field and does not erase SEC filing evidence.