AMPH Institutional Ownership
Amphastar Pharmaceuticals, Inc.
Latest close $20.78 as of Aug 7, 2026
AMPH institutional ownership at a glance
Follow Amphastar Pharmaceuticals, Inc. institutional ownership through recent Schedule 13G and 13D filings. Compare reported shares, ownership percentages, filing dates, and changes in beneficial ownership over time.
Latest filing: Dimensional Fund Advisors filed Initial Schedule 13G on Jul 14, 2026, reporting 2.3M shares and 5.20% beneficial ownership.
How to read Schedule 13 ownership changes
Schedule 13G/13D reports beneficial ownership at an observation date. “Accumulation” or “reduction” is inferred from changes in reported shares when available; it is not a list of individual trades or exact execution prices.
Form 13F rows are quarter-end holding context only and do not establish an exact entry date.
For more context, see how to read a Schedule 13G, filing date vs event date, or Schedule 13G vs Schedule 13D.
Institutional Research
This gauge summarizes recent agreement across tracked institutional activity.
1 reducing across 1 comparable institution.
The overall consensus is public. Detailed holder comparisons, breadth history, ownership charts, and filing-specific signal analysis remain part of Investor and Pro research.
Price context
52-week position is market context and does not change the institutional consensus score.
Tracked institutions
Public holder names and filing freshness. Detailed institution-by-institution analysis is locked.
Beneficial ownership filing history
Showing 3 of 4 filing(s) · 1 older require more history access| Holder | Observed / filed | Reported change | Shares | Ownership | Observation | Filing | Latest |
|---|---|---|---|---|---|---|---|
| Dimensional Fund Advisors CIK0000354204 | Jun 30, 2026 observed Jul 14, 2026 filed · 14d Initial Schedule 13G | Initial Schedule 13G | 2.3M | 5.20% | $20.18 | $18.81 | $20.78 |
| BlackRock CIK0002012383 | Sep 30, 2025 observed Oct 17, 2025 filed · 17d Schedule 13G amendment | Earliest Schedule 13G amendment found | 5.3M | 12.00% | $26.65 | $23.78 | $20.78 |
| BlackRock CIK0002012383 | Sep 30, 2024 quarter end Nov 13, 2024 filed Form 13F quarter-end evidence | Earlier Form 13F quarter-end holding Quarter-end holding evidence; no ownership percentage or signal. | 6.0M | $48.53 | $45.48 | $20.78 |
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