Lsv Asset Management
· Added
Change
+541K
Date
Q1 2026
AM
| Investor | Type | Est. change | Change | Δ Own | Date | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Lsv Asset Management
· Added
Change
+541K
Date
Q1 2026
|
Lsv Asset Management | Added· Q1 2026 | – | +541K | – | Q1 2026 | |||||
|
Td Asset Management Inc
· Reduced
Change
−422K
Date
Q1 2026
|
Td Asset Management Inc | Reduced· Q1 2026 | – | −422K | – | Q1 2026 | |||||
|
Hotchkis & Wiley Capital Management LLC
· Exited
Change
−403K
Δ Own
−100.0%
Date
Q1 2026
|
Hotchkis & Wiley Capital Management LLC | Exited· Q1 2026 | – | −403K | −100.0% | Q1 2026 | |||||
|
American Century Companies Inc
· Added
Change
+352K
Date
Q1 2026
|
American Century Companies Inc | Added· Q1 2026 | – | +352K | – | Q1 2026 | |||||
|
Clark Capital Management Group, Inc.
· Exited
Change
−317K
Δ Own
−100.0%
Date
Q1 2026
|
Clark Capital Management Group, Inc. | Exited· Q1 2026 | – | −317K | −100.0% | Q1 2026 | |||||
|
Arrowstreet Capital, Limited Partnership
· Reduced
Change
−234K
Date
Q1 2026
|
Arrowstreet Capital, Limited Partnership | Reduced· Q1 2026 | – | −234K | – | Q1 2026 | |||||
|
Dimensional
· Added
Change
+228K
Date
Q1 2026
|
Dimensional | Added· Q1 2026 | – | +228K | – | Q1 2026 | |||||
|
Epoch Investment Partners, Inc.
· Reduced
Change
−228K
Date
Q1 2026
|
Epoch Investment Partners, Inc. | Reduced· Q1 2026 | – | −228K | – | Q1 2026 | |||||
|
Goldman Sachs Group Inc
· Reduced
Change
−227K
Date
Q1 2026
|
Goldman Sachs Group Inc | Reduced· Q1 2026 | – | −227K | – | Q1 2026 | |||||
|
Marshall Wace, LLP
· Reduced
Change
−212K
Date
Q1 2026
|
Marshall Wace, LLP | Reduced· Q1 2026 | – | −212K | – | Q1 2026 | |||||
|
Pacer Advisors, Inc.
· Exited
Change
−178K
Δ Own
−100.0%
Date
Q1 2026
|
Pacer Advisors, Inc. | Exited· Q1 2026 | – | −178K | −100.0% | Q1 2026 | |||||
|
Morgan Stanley
· Reduced
Change
−171K
Date
Q1 2026
|
Morgan Stanley | Reduced· Q1 2026 | – | −171K | – | Q1 2026 | |||||
|
UBS Group AG
· Added
Change
+164K
Date
Q1 2026
|
UBS Group AG | Added· Q1 2026 | – | +164K | – | Q1 2026 | |||||
|
Citadel Advisors LLC
· Reduced
Change
−163K
Δ Own
−71.3%
Date
Q1 2026
|
Citadel Advisors LLC | Reduced· Q1 2026 | – | −163K | −71.3% | Q1 2026 | |||||
|
Boston Trust Walden Corp
· Reduced
Change
−142K
Date
Q1 2026
|
Boston Trust Walden Corp | Reduced· Q1 2026 | – | −142K | – | Q1 2026 | |||||
| Insider | Title | Type | Price | Qty | Value | Owned | ΔOwn | Trade date | Filed date | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Pierce Anthony T.
· Director
2 operations
25K
|
Pierce Anthony T. | Director | 2 operations | – | 25K | – | 17K | – | Jul 9, 2026 | Jul 13, 2026 | |||||||||
|
Lee Howard
· Director
Tax withholding or exercise payment (F)
-$14K
|
Lee Howard | Director | Tax withholding or exercise payment (F) | $18.45 | -769 | -$14K | 159K | – | Jun 2, 2026 | Jun 3, 2026 | |||||||||
|
Prins Richard K.
· Director
2 operations
26K
|
Prins Richard K. | Director | 2 operations | – | 26K | – | 17K | – | Jun 1, 2026 | Jun 3, 2026 | |||||||||
|
Lee Howard
· Director
2 operations
26K
|
Lee Howard | Director | 2 operations | – | 26K | – | 17K | – | Jun 1, 2026 | Jun 3, 2026 | |||||||||
|
Zasloff Michael A.
· Director
2 operations
26K
|
Zasloff Michael A. | Director | 2 operations | – | 26K | – | 17K | – | Jun 1, 2026 | Jun 3, 2026 | |||||||||
|
Gerst Diane G.
· Director
2 operations
26K
|
Gerst Diane G. | Director | 2 operations | – | 26K | – | 17K | – | Jun 1, 2026 | Jun 3, 2026 | |||||||||
|
Gaugh David Russell
· Director
2 operations
26K
|
Gaugh David Russell | Director | 2 operations | – | 26K | – | 17K | – | Jun 1, 2026 | Jun 3, 2026 | |||||||||
|
Deflin Gayle
· Director
2 operations
26K
|
Deflin Gayle | Director | 2 operations | – | 26K | – | 17K | – | Jun 1, 2026 | Jun 3, 2026 | |||||||||
|
Liawatidewi Yakob
· Director, Officer
Tax withholding or exercise payment (F)
-$19K
|
Liawatidewi Yakob | Director, Officer | Tax withholding or exercise payment (F) | $18.18 | -1K | -$19K | 122K | – | Mar 15, 2026 | Mar 17, 2026 | |||||||||
|
Zhou Rong
· Officer
Tax withholding or exercise payment (F)
-$22K
|
Zhou Rong | Officer | Tax withholding or exercise payment (F) | $18.18 | -1K | -$22K | 172K | – | Mar 15, 2026 | Mar 17, 2026 | |||||||||
|
Peters William J.
· Director
Tax withholding or exercise payment (F)
-$36K
|
Peters William J. | Director | Tax withholding or exercise payment (F) | $18.18 | -2K | -$36K | 175K | – | Mar 15, 2026 | Mar 17, 2026 | |||||||||
|
Zhang Jack Y.
· Director, Officer, 10% Owner
2 operations
-$231K
|
Zhang Jack Y. | Director, Officer, 10% Owner | 2 operations | $18.18 | -13K | -$231K | 1.2M | – | Mar 15, 2026 | Mar 17, 2026 | |||||||||
|
Peters William J.
· Director, Officer
Tax withholding or exercise payment (F)
-$62K
|
Peters William J. | Director, Officer | Tax withholding or exercise payment (F) | $18.91 | -3K | -$62K | 177K | – | Mar 10, 2026 | Mar 11, 2026 | |||||||||
|
Zhou Rong
· Officer
Tax withholding or exercise payment (F)
-$42K
|
Zhou Rong | Officer | Tax withholding or exercise payment (F) | $18.91 | -2K | -$42K | 173K | – | Mar 10, 2026 | Mar 11, 2026 | |||||||||
|
Liawatidewi Yakob
· Director, Officer
Tax withholding or exercise payment (F)
-$35K
|
Liawatidewi Yakob | Director, Officer | Tax withholding or exercise payment (F) | $18.91 | -2K | -$35K | 123K | – | Mar 10, 2026 | Mar 11, 2026 | |||||||||
N
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227 reporting institutions disclosed AMPH position changes in the Q1 2026 snapshot.
For each manager, WhoBought compares accepted consecutive 13F share counts. Share change is current shares minus prior shares. Estimated dollar change is that signed share change multiplied by the split-adjusted quarter-mean close. The activity table on this page uses Q1 2026.
An investor crossing 5% of a share class generally files Schedule 13D for activist intent or Schedule 13G for a passive position. The technical form names appear here rather than in the activity rows.
Ownership and institutional activity come from SEC Form 13F filings. Insider activity comes from SEC Form 4, and large-shareholder activity from SEC Schedules 13D and 13G. FMP supplies price data only. Company logos use the local verified Parqet cache with one shared fallback.
Form 13F is a quarterly disclosure and is normally filed after the quarter ends. Every ownership and activity value therefore names its represented period; it is not presented as a live position.
A muted dash marks a missing table value. It means the filing omitted the value, comparable data is unavailable, or no prior position exists for comparison.