Samsara Biocapital, LLC
· New
Change
+3.4M
Date
Q1 2026
CH
| Investor | Type | Est. change | Change | Δ Own | Date | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
|
Samsara Biocapital, LLC
· New
Change
+3.4M
Date
Q1 2026
|
Samsara Biocapital, LLC | New· Q1 2026 | – | +3.4M | – | Q1 2026 | |||||
|
Vanguard
· Reduced
Change
−3.0M
Date
Q1 2026
|
Vanguard | Reduced· Q1 2026 | – | −3.0M | – | Q1 2026 | |||||
|
Alyeska Investment Group, L.P.
· New
Change
+2.2M
Date
Q1 2026
|
Alyeska Investment Group, L.P. | New· Q1 2026 | – | +2.2M | – | Q1 2026 | |||||
|
Two Sigma Investments, LP
· Added
Change
+1.8M
Δ Own
+356.9%
Date
Q1 2026
|
Two Sigma Investments, LP | Added· Q1 2026 | – | +1.8M | +356.9% | Q1 2026 | |||||
|
Propel Bio Management, LLC
· New
Change
+1.4M
Date
Q1 2026
|
Propel Bio Management, LLC | New· Q1 2026 | – | +1.4M | – | Q1 2026 | |||||
|
Hudson Bay Capital Management LP
· Added
Change
+870K
Date
Q1 2026
|
Hudson Bay Capital Management LP | Added· Q1 2026 | – | +870K | – | Q1 2026 | |||||
|
Tang Capital Management LLC
· Reduced
Change
−838K
Date
Q1 2026
|
Tang Capital Management LLC | Reduced· Q1 2026 | – | −838K | – | Q1 2026 | |||||
|
Jane Street Group, LLC
· Reduced
Change
−563K
Date
Q1 2026
|
Jane Street Group, LLC | Reduced· Q1 2026 | – | −563K | – | Q1 2026 | |||||
|
Goldman Sachs Group Inc
· Added
Change
+389K
Date
Q1 2026
|
Goldman Sachs Group Inc | Added· Q1 2026 | – | +389K | – | Q1 2026 | |||||
|
Geode
· Added
Change
+376K
Date
Q1 2026
|
Geode | Added· Q1 2026 | – | +376K | – | Q1 2026 | |||||
|
Millennium Management LLC
· Reduced
Change
−348K
Date
Q1 2026
|
Millennium Management LLC | Reduced· Q1 2026 | – | −348K | – | Q1 2026 | |||||
|
AQR Capital Management LLC
· Added
Change
+320K
Date
Q1 2026
|
AQR Capital Management LLC | Added· Q1 2026 | – | +320K | – | Q1 2026 | |||||
|
Informed Momentum Co LLC
· New
Change
+310K
Date
Q1 2026
|
Informed Momentum Co LLC | New· Q1 2026 | – | +310K | – | Q1 2026 | |||||
|
Two Sigma Advisers, LP
· Exited
Change
−308K
Δ Own
−100.0%
Date
Q1 2026
|
Two Sigma Advisers, LP | Exited· Q1 2026 | – | −308K | −100.0% | Q1 2026 | |||||
|
Simplify Asset Management Inc.
· New
Change
+253K
Date
Q1 2026
|
Simplify Asset Management Inc. | New· Q1 2026 | – | +253K | – | Q1 2026 | |||||
| Insider | Title | Type | Price | Qty | Value | Owned | ΔOwn | Trade date | Filed date | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Satvat Ali J.
· Director
2 operations
90K
|
Satvat Ali J. | Director | 2 operations | – | 90K | – | 60K | – | Jun 5, 2026 | Jun 9, 2026 | |||||||||
|
Karachun Rita A.
· Director
2 operations
90K
|
Karachun Rita A. | Director | 2 operations | – | 90K | – | 60K | – | Jun 5, 2026 | Jun 9, 2026 | |||||||||
|
Newcomer Lee Nisley
· Director
2 operations
90K
|
Newcomer Lee Nisley | Director | 2 operations | – | 90K | – | 60K | – | Jun 5, 2026 | Jun 9, 2026 | |||||||||
|
Ryan Michael Lee
· Director
2 operations
90K
|
Ryan Michael Lee | Director | 2 operations | – | 90K | – | 60K | – | Jun 5, 2026 | Jun 9, 2026 | |||||||||
|
O'Donnell-Tormey Jill
· Director
2 operations
90K
|
O'Donnell-Tormey Jill | Director | 2 operations | – | 90K | – | 60K | – | Jun 5, 2026 | Jun 9, 2026 | |||||||||
|
Wahlstrom Mats
· Director
2 operations
90K
|
Wahlstrom Mats | Director | 2 operations | – | 90K | – | 60K | – | Jun 5, 2026 | Jun 9, 2026 | |||||||||
|
Newton Charles W.
· Director
2 operations
90K
|
Newton Charles W. | Director | 2 operations | – | 90K | – | 60K | – | Jun 5, 2026 | Jun 9, 2026 | |||||||||
|
McMichael Bryan J.
· CFO
6 operations
-220K
|
McMichael Bryan J. | CFO | 6 operations | – | -220K | – | 0 | – | May 29, 2026 | Jun 2, 2026 | |||||||||
|
McMichael Bryan J.
· CFO
6 operations
220K
|
McMichael Bryan J. | CFO | 6 operations | – | 220K | – | 30K | – | May 29, 2026 | Jun 2, 2026 | |||||||||
|
Lanfear Dennis M.
· Director
9 operations
-3.2M
|
Lanfear Dennis M. | Director | 9 operations | – | -3.2M | – | 0 | – | May 29, 2026 | Jun 2, 2026 | |||||||||
|
Lanfear Dennis M.
· Director
9 operations
3.2M
|
Lanfear Dennis M. | Director | 9 operations | – | 3.2M | – | 225K | – | May 29, 2026 | Jun 2, 2026 | |||||||||
|
Lanfear Dennis M.
· Director, Officer
2 operations
1.1M
|
Lanfear Dennis M. | Director, Officer | 2 operations | – | 1.1M | – | 750K | – | Jan 23, 2026 | Jan 26, 2026 | |||||||||
|
McMichael Bryan J.
· Officer
2 operations
338K
|
McMichael Bryan J. | Officer | 2 operations | – | 338K | – | 225K | – | Jan 22, 2026 | Jan 26, 2026 | |||||||||
|
McMichael Bryan J.
· Officer
Tax withholding or exercise payment (F)
-$3K
|
McMichael Bryan J. | Officer | Tax withholding or exercise payment (F) | $1.55 | -2K | -$3K | 21K | – | Jan 20, 2026 | Jan 22, 2026 | |||||||||
|
Lanfear Dennis M.
· Director, Officer
Tax withholding or exercise payment (F)
-$18K
|
Lanfear Dennis M. | Director, Officer | Tax withholding or exercise payment (F) | $1.55 | -12K | -$18K | 673K | – | Jan 20, 2026 | Jan 22, 2026 | |||||||||
N
A
M
M
G
A
129 reporting institutions disclosed CHRS 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.