undamentalytics Newsletter

Amphastar Pharmaceuticals, Inc. insider trading

Every open-market purchase and sale by Amphastar Pharmaceuticals, Inc.'s officers, directors and largest shareholders since November 4, 2021, and what the share price did next.

No insider has bought shares on the open market in five years.

Insider purchase Insider sale Marker size reflects trade value. Weekly closes adjusted for splits; may be delayed.
Amphastar Pharmaceuticals, Inc. insider open-market trades
DateInsiderTrade SharesPriceValue 1M after 3M after 6M after

From insiders' Form 4 filings with the SEC: open-market purchases and sales only (awards, option exercises and shares withheld for tax are excluded), combined to one line per insider per day. "Plan" marks trades the filing says were made under a pre-set Rule 10b5-1 trading plan, which are scheduled in advance. Price changes run from the close on the trade date; hover a figure for the change relative to the S&P 500. Past moves don't predict future ones.

Does following Amphastar Pharmaceuticals, Inc.’s insiders pay?

From August 19, 2014 to September 17, 2026, 15 insiders reported 8 open-market purchases and 114 sales not made under a pre-set plan in Amphastar Pharmaceuticals, Inc. Twelve months after each purchase was reported, the shares were +20.3% against the S&P 500 on average (median +33.1%), over 8 purchases with a full year of prices; 88% beat the index. After sales, the shares moved −9.6% against the index over 12 months (a negative figure means selling was the right call). That rests on fewer than 20 purchases, too few to read much into. Buying each purchase the day after it was reported, an equal amount each, held 12 months or until that insider reported a sale, would have turned $10,000 on August 20, 2014 into $18,503 by November 2, 2026, +5.2% a year. It held shares 21% of the time; the S&P 500 on those same days, with Treasury bills otherwise, made $16,361 (+4.1% a year), and held throughout $46,626 (+13.5%).

$0$20.0k$40.0k 2014201620182020202220242026 $46.6k$18.5k$16.4k
Copying Amphastar Pharmaceuticals, Inc.'s insidersS&P 500, same days investedS&P 500, held throughout $10,000 copying every open-market purchase by Amphastar Pharmaceuticals, Inc.'s insiders from August 20, 2014, before costs and taxes, marked weekly. Uninvested money earns the Treasury bill rate; the portfolio held shares 21% of the time.
Amphastar Pharmaceuticals, Inc.: each insider's record
InsiderRolePurchases12 months after their purchasesBeat the S&P 500Sales12 months after their salesLatest report
Prins Richard K Director 1 +33.1% (1) 100% 37 −11.1% (35) August 12, 2026
Zhou Rong SENIOR EVP, PRODUCTION CENTER 0 — — 17 −21.6% (14) September 17, 2026
Zasloff Michael A Director 1 +35.8% (1) 100% 12 −12.3% (12) March 6, 2024
Lee Howard Director 1 +14.1% (1) 100% 11 +1.7% (11) June 5, 2023
Petersen Floyd F. Director 1 +33.1% (1) 100% 11 +3.5% (9) December 15, 2025
Liawatidewi Yakob SVP Corp Admin Center 0 — — 8 −2.0% (8) May 18, 2021
Koo Richard Director 1 +33.1% (1) 100% 3 +12.0% (3) June 2, 2021
Peters William J CFO, EVP & Treasurer 0 — — 4 +15.8% (4) March 18, 2022
Deflin Gayle Director 0 — — 3 −38.0% (3) November 15, 2023
Shohet Stephen B. Director 1 +33.1% (1) 100% 2 −32.8% (2) December 12, 2018
Gerst Diane G. EVP, QA & Regulatory Affairs 0 — — 2 −22.3% (2) December 16, 2016
Luo Mary Z. COO,Chief Scientist & Chairman 0 — — 2 −26.6% (2) September 12, 2019
Zhang Jack Y. CEO & Chief Scientific Officer 1 +21.5% (1) 100% 1 −31.9% (1) December 17, 2018
Maris David Director 1 −41.3% (1) 0% 0 — August 18, 2020
Shandell Jason B. President and General Counsel 0 — — 1 −18.4% (1) June 1, 2017

Moves are the shares’ return including dividends minus the S&P 500’s, from the close on the first trading day after each report; the number of trades with a finished 12-month window is in brackets. Green means the trade went the insider’s way (a purchase ahead of the index, a sale followed by the shares trailing it). A trade reported both by a director or officer and by a fund or company they are linked to counts once here, under the person. Purchases count only where the share price actually traded was at least $5. These figures describe what the shares did, not why anyone traded. Insiders across all companies.

When several insiders traded Amphastar Pharmaceuticals, Inc.

Months when 2 or more insiders became net buyers, or 3 or more net sellers, of Amphastar Pharmaceuticals, Inc. in reports dated in the 91 days before the month end, and how the stock did against the S&P 500 from that month end. After the 1 buying crowd with six months of prices, it averaged +9.7% against the index. After 12 selling crowds, −14.0%. One company's history is too short to judge by; the test across every company is the better guide.

MonthCrowd3 months on, vs S&P 5006 months12 months
December 31, 20253 selling−20.1%−37.5%not yet
August 30, 20243 selling−14.5%−46.5%−56.7%
December 29, 20233 selling−41.1%−55.5%−64.9%
May 31, 20235 selling+14.2%+16.0%−32.6%
March 31, 20223 selling+13.7%−1.5%+13.7%
May 28, 20215 selling−5.5%−4.7%+105.3%
May 29, 20205 selling−6.0%−24.3%−38.7%
September 30, 20194 selling−11.8%−13.0%−20.2%
November 30, 20183 selling+10.1%−13.0%−26.9%
June 30, 20174 selling−4.4%−3.8%−28.4%
June 30, 20163 selling+13.9%+5.7%−7.0%
December 31, 20154 selling−11.1%+10.4%+17.4%

Colours show whether the crowd was right: green when buyers were followed by a rise above the index, or sellers by a fall below it. Latest 12 of 13. Total returns from the month end; past patterns are not a forecast.

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