Barrow Hanley Mewhinney & Strauss LLC
· New
Change
+1.1M
Date
Q1 2026
AM
| Investor | Type | Est. change | Change | Δ Own | Date | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Barrow Hanley Mewhinney & Strauss LLC
· New
Change
+1.1M
Date
Q1 2026
|
Barrow Hanley Mewhinney & Strauss LLC | New· Q1 2026 | – | +1.1M | – | Q1 2026 | |||||
|
Atreides Management, LP
· Exited
Change
−1.0M
Δ Own
−100.0%
Date
Q1 2026
|
Atreides Management, LP | Exited· Q1 2026 | – | −1.0M | −100.0% | Q1 2026 | |||||
|
Vanguard
· Added
Change
+610K
Date
Q1 2026
|
Vanguard | Added· Q1 2026 | – | +610K | – | Q1 2026 | |||||
|
Driehaus Capital Management LLC
· Exited
Change
−500K
Δ Own
−100.0%
Date
Q1 2026
|
Driehaus Capital Management LLC | Exited· Q1 2026 | – | −500K | −100.0% | Q1 2026 | |||||
|
Hood River Capital Management LLC
· New
Change
+399K
Date
Q1 2026
|
Hood River Capital Management LLC | New· Q1 2026 | – | +399K | – | Q1 2026 | |||||
|
BNP Paribas Financial Markets
· Added
Change
+354K
Date
Q1 2026
|
BNP Paribas Financial Markets | Added· Q1 2026 | – | +354K | – | Q1 2026 | |||||
|
Portolan Capital Management, LLC
· New
Change
+296K
Date
Q1 2026
|
Portolan Capital Management, LLC | New· Q1 2026 | – | +296K | – | Q1 2026 | |||||
|
Qube Research & Technologies Ltd
· Reduced
Change
−270K
Date
Q1 2026
|
Qube Research & Technologies Ltd | Reduced· Q1 2026 | – | −270K | – | Q1 2026 | |||||
|
Legal & General
· Added
Change
+252K
Date
Q1 2026
|
Legal & General | Added· Q1 2026 | – | +252K | – | Q1 2026 | |||||
|
Tudor Investment Corp Et Al
· Exited
Change
−252K
Δ Own
−100.0%
Date
Q1 2026
|
Tudor Investment Corp Et Al | Exited· Q1 2026 | – | −252K | −100.0% | Q1 2026 | |||||
|
Jane Street Group, LLC
· Exited
Change
−243K
Δ Own
−100.0%
Date
Q1 2026
|
Jane Street Group, LLC | Exited· Q1 2026 | – | −243K | −100.0% | Q1 2026 | |||||
|
Arrowstreet Capital, Limited Partnership
· Reduced
Change
−236K
Date
Q1 2026
|
Arrowstreet Capital, Limited Partnership | Reduced· Q1 2026 | – | −236K | – | Q1 2026 | |||||
|
BlackRock
· Added
Change
+232K
Date
Q1 2026
|
BlackRock | Added· Q1 2026 | – | +232K | – | Q1 2026 | |||||
|
T. Rowe Price Associates
· Reduced
Change
−216K
Date
Q1 2026
|
T. Rowe Price Associates | Reduced· Q1 2026 | – | −216K | – | Q1 2026 | |||||
|
Royce & Associates LP
· Added
Change
+156K
Date
Q1 2026
|
Royce & Associates LP | Added· Q1 2026 | – | +156K | – | Q1 2026 | |||||
| Insider | Title | Type | Price | Qty | Value | Owned | ΔOwn | Trade date | Filed date | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Dambier Laura A.
· Director
Sell
−$151K
|
Dambier Laura A. | Director | Sell | $37.63 | −4K | −$151K | 15K | – | Jun 11, 2026 | Jun 12, 2026 | |||||||||
|
Kosiba John W. Jr
· Officer
2 operations
−$254K
|
Kosiba John W. Jr | Officer | 2 operations | $37.33–$37.85 | −7K | −$254K | 334K | – | Jun 11, 2026 | Jun 11, 2026 | |||||||||
|
McGahn Daniel P.
· Director
2 operations
−$604K
|
McGahn Daniel P. | Director | 2 operations | $37.28–$37.85 | −16K | −$604K | 1.1M | – | Jun 11, 2026 | Jun 11, 2026 | |||||||||
|
Kosiba John W. Jr
· Officer
2 operations
−$202K
|
Kosiba John W. Jr | Officer | 2 operations | $41.50–$42.35 | −5K | −$202K | 341K | – | Jun 8, 2026 | Jun 10, 2026 | |||||||||
|
McGahn Daniel P.
· Director
2 operations
−$404K
|
McGahn Daniel P. | Director | 2 operations | $41.39–$42.19 | −10K | −$404K | 1.1M | – | Jun 8, 2026 | Jun 10, 2026 | |||||||||
|
Kosiba John W. Jr
· Officer
3 operations
−$316K
|
Kosiba John W. Jr | Officer | 3 operations | $48.31–$50.83 | −6K | −$316K | 346K | – | Jun 3, 2026 | Jun 3, 2026 | |||||||||
|
McGahn Daniel P.
· Director
4 operations
−$630K
|
McGahn Daniel P. | Director | 4 operations | $48.31–$50.99 | −13K | −$630K | 1.2M | – | Jun 3, 2026 | Jun 3, 2026 | |||||||||
|
Kosiba John W. Jr
· Officer
4 operations
−$1.5M
|
Kosiba John W. Jr | Officer | 4 operations | $49.46–$52.19 | −30K | −$1.5M | 352K | – | Jun 2, 2026 | Jun 3, 2026 | |||||||||
|
McGahn Daniel P.
· Director
4 operations
−$3.7M
|
McGahn Daniel P. | Director | 4 operations | $49.45–$52.14 | −73K | −$3.7M | 1.2M | – | Jun 2, 2026 | Jun 3, 2026 | |||||||||
|
Kosiba John W. Jr
· Officer
Grant (A)
30K
|
Kosiba John W. Jr | Officer | Grant (A) | – | 30K | – | 383K | – | Jun 1, 2026 | Jun 3, 2026 | |||||||||
|
McGahn Daniel P.
· Director
Grant (A)
60K
|
McGahn Daniel P. | Director | Grant (A) | – | 60K | – | 1.2M | – | Jun 1, 2026 | Jun 3, 2026 | |||||||||
|
Donnelly Terence Robert
· Director
Grant (A)
3K
|
Donnelly Terence Robert | Director | Grant (A) | – | 3K | – | 3K | – | Apr 3, 2026 | Apr 7, 2026 | |||||||||
|
Oliver David R. Jr
· Director
Grant (A)
3K
|
Oliver David R. Jr | Director | Grant (A) | – | 3K | – | 64K | – | Apr 3, 2026 | Apr 7, 2026 | |||||||||
|
Littlefield Barbara G.
· Director
Grant (A)
3K
|
Littlefield Barbara G. | Director | Grant (A) | – | 3K | – | 35K | – | Apr 3, 2026 | Apr 7, 2026 | |||||||||
|
Klein Margaret D.
· Director
Grant (A)
3K
|
Klein Margaret D. | Director | Grant (A) | – | 3K | – | 19K | – | Apr 3, 2026 | Apr 7, 2026 | |||||||||
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250 reporting institutions disclosed AMSC 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.