Amphastar Pharmaceuticals In (AMPH) Held by Superinvestors
AMPHASTAR PHARMACEUTICALS IN (AMPH) is currently held by 1 superinvestors tracked by InsiderSet, with a combined reported market value of approximately $10.60M based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026.
Renaissance Technologies LLC is currently the largest disclosed institutional shareholder of AMPH tracked by InsiderSet, reporting ownership valued at approximately $10.60M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $13.20M, representing an estimated gain of +24.58% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 100% of the total disclosed AMPH value among the investors covered in this analysis. Major shareholders include Renaissance Technologies LLC, and several other long-term asset managers with concentrated positions in AMPHASTAR PHARMACEUTICALS IN (AMPH).
This page ranks the largest institutional AMPH shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Renaissance Technologies LLC | Jim Simons | 0.01% | 525,100 | $10,596,518 | $13,201,014 | +$2,604,496 | +24.58% |
Frequently asked questions about AMPH
Who are the largest superinvestors holding AMPH?
The largest superinvestors holding AMPH in the latest SEC Form 13F filings include Renaissance Technologies LLC. InsiderSet ranks these superinvestors by their latest reported AMPH position.
What does the AMPH superinvestors page include?
This page tracks AMPH positions reported by a curated group of notable institutional investors and fund managers through SEC Form 13F. AMPHASTAR PHARMACEUTICALS IN (AMPH) on this page reflects disclosed 13F holdings among those superinvestors, not every institutional shareholder of the stock.
How many superinvestors hold AMPH?
InsiderSet currently tracks 1 superinvestors reporting AMPH holdings in the latest available 13F data. This is the curated set on this page, not the total number of institutions that own AMPH.
How much AMPH stock do superinvestors hold?
Superinvestors tracked by InsiderSet disclosed approximately $10.60M in AMPH holdings for Q2 2026. This figure is reported 13F value as of the filing period, not necessarily today's market value, and it covers the curated superinvestors on this page rather than every institutional filer.
When were AMPH superinvestor holdings last updated?
The latest AMPH superinvestor holdings on InsiderSet are based on SEC Form 13F filings for the quarter ended June 30, 2026. Form 13F filings are generally reported after the quarter ends, so the holdings shown represent the latest publicly disclosed positions rather than real-time holdings.
Are superinvestor AMPH holdings real-time?
No. Form 13F data is not real-time. It represents positions reported by these superinvestors as of the end of the reporting quarter. A superinvestor may have changed its AMPH position after the reporting date.
Are superinvestors buying or selling AMPH?
Buying and selling can be analyzed by comparing AMPH positions across consecutive 13F reporting periods. InsiderSet's AMPH Ownership Changes page shows institutions that increased, reduced, initiated, or exited positions based on reported 13F holdings. View AMPH ownership changes.
How have superinvestor AMPH holdings changed over time?
InsiderSet tracks AMPH holdings among these superinvestors across multiple 13F reporting periods, so holder counts, reported value, and reported shares can be compared over time.