Atreides Management, LP
· Exited
Change
−1.0M
Δ Own
−100.0%
Date
Q1 2026
AM
| Investor | Type | Est. change | Change | Δ Own | Date | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
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 | |||||
|
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 | |||||
|
Qube Research & Technologies Ltd
· Reduced
Change
−270K
Date
Q1 2026
|
Qube Research & Technologies Ltd | Reduced· Q1 2026 | – | −270K | – | 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 | |||||
|
T. Rowe Price Associates
· Reduced
Change
−216K
Date
Q1 2026
|
T. Rowe Price Associates | Reduced· Q1 2026 | – | −216K | – | Q1 2026 | |||||
|
Two Sigma Investments, LP
· Reduced
Change
−153K
Δ Own
−47.4%
Date
Q1 2026
|
Two Sigma Investments, LP | Reduced· Q1 2026 | – | −153K | −47.4% | Q1 2026 | |||||
|
Invesco Ltd.
· Reduced
Change
−145K
Δ Own
−37.6%
Date
Q1 2026
|
Invesco Ltd. | Reduced· Q1 2026 | – | −145K | −37.6% | Q1 2026 | |||||
|
UBS Group AG
· Reduced
Change
−145K
Date
Q1 2026
|
UBS Group AG | Reduced· Q1 2026 | – | −145K | – | Q1 2026 | |||||
|
Renaissance Technologies LLC
· Exited
Change
−140K
Δ Own
−100.0%
Date
Q1 2026
|
Renaissance Technologies LLC | Exited· Q1 2026 | – | −140K | −100.0% | Q1 2026 | |||||
|
Citadel Advisors LLC
· Reduced
Change
−121K
Δ Own
−35.8%
Date
Q1 2026
|
Citadel Advisors LLC | Reduced· Q1 2026 | – | −121K | −35.8% | Q1 2026 | |||||
|
Y-Intercept (hong Kong) Ltd
· Exited
Change
−120K
Δ Own
−100.0%
Date
Q1 2026
|
Y-Intercept (hong Kong) Ltd | Exited· Q1 2026 | – | −120K | −100.0% | Q1 2026 | |||||
|
Nomura Asset Management International Inc.
· Reduced
Change
−80K
Date
Q1 2026
|
Nomura Asset Management International Inc. | Reduced· Q1 2026 | – | −80K | – | Q1 2026 | |||||
|
Capital Fund Management S.A.
· Exited
Change
−79K
Δ Own
−100.0%
Date
Q1 2026
|
Capital Fund Management S.A. | Exited· Q1 2026 | – | −79K | −100.0% | 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.