BOSTON, MA
X4 PHARMACEUTICALS, INCXFOR— Latest position per institution from SEC 13F filings
15
Institutional holders
91.49M
Total shares held
423.96M
Estimated value
4.57M
Avg. position size
MORGAN STANLEY
CIK 895421
Shares
9.46M
Value
44.18M
Filed
Jun 30, 2026
FMR LLC
CIK 315066
Shares
8.32M
Value
38.86M
Filed
Jun 30, 2026
BAIN CAPITAL LIFE SCIENCES INVESTORS, LLC
CIK 1703031
Shares
7.97M
Value
37.21M
Filed
Jun 30, 2026
PERCEPTIVE ADVISORS LLC
CIK 1224962
Shares
7.93M
Value
37.05M
Filed
Jun 30, 2026
SATURN V CAPITAL MANAGEMENT LP
CIK 1964437
Shares
6.97M
Value
32.57M
Filed
Jun 30, 2026
EMPERY ASSET MANAGEMENT, LP
CIK 1469336
Shares
6.93M
Value
32.37M
Filed
Jun 30, 2026
DEEP TRACK CAPITAL, LP
CIK 1856083
Shares
5.88M
Value
27.45M
Filed
Jun 30, 2026
BLACKROCK, INC.
CIK 2012383
Shares
5.55M
Value
25.94M
Filed
Jun 30, 2026
KALEHUA CAPITAL MANAGEMENT LLC
CIK 2106181
Shares
3.72M
Value
17.39M
Filed
Jun 30, 2026
VANGUARD CAPITAL MANAGEMENT LLC
CIK 2100119
Shares
3.72M
Value
17.35M
Filed
Jun 30, 2026
VANGUARD GROUP INC
CIK 102909
Shares
3.42M
Value
13.69M
Filed
Dec 31, 2025
ROSALIND ADVISORS, INC.
CIK 1622627
Shares
3.21M
Value
15.01M
Filed
Jun 30, 2026
BRAIDWELL LP
CIK 1920938
Shares
2.92M
Value
13.65M
Filed
Jun 30, 2026
BLACKSTONE INC.
CIK 1393818
Shares
2.68M
Value
12.52M
Filed
Jun 30, 2026
TRAILS EDGE CAPITAL PARTNERS, LP
CIK 2077247
Shares
2.57M
Value
12.01M
Filed
Jun 30, 2026
NANTAHALA CAPITAL MANAGEMENT, LLC
CIK 1472322
Shares
2.45M
Value
11.44M
Filed
Jun 30, 2026
BVF INC/IL
CIK 1056807
Shares
2.23M
Value
10.43M
Filed
Jun 30, 2026
GEODE CAPITAL MANAGEMENT, LLC
CIK 1214717
Shares
2.10M
Value
9.80M
Filed
Jun 30, 2026
VENROCK ADVISER, LLC
CIK 1615982
Shares
1.93M
Value
9.03M
Filed
Jun 30, 2026
SIREN, L.L.C.
CIK 2005245
Shares
1.50M
Value
6M
Filed
Dec 31, 2025
| # | Institution | CIK | Shares | Est. Value | Period |
|---|---|---|---|---|---|
| 1 | MORGAN STANLEY | 895421 | 9.46M | 44.18M | Jun 30, 2026 |
| 2 | FMR LLC | 315066 | 8.32M | 38.86M | Jun 30, 2026 |
| 3 | BAIN CAPITAL LIFE SCIENCES INVESTORS, LLC | 1703031 | 7.97M | 37.21M | Jun 30, 2026 |
| 4 | PERCEPTIVE ADVISORS LLC | 1224962 | 7.93M | 37.05M | Jun 30, 2026 |
| 5 | SATURN V CAPITAL MANAGEMENT LP | 1964437 | 6.97M | 32.57M | Jun 30, 2026 |
| 6 | EMPERY ASSET MANAGEMENT, LP | 1469336 | 6.93M | 32.37M | Jun 30, 2026 |
| 7 | DEEP TRACK CAPITAL, LP | 1856083 | 5.88M | 27.45M | Jun 30, 2026 |
| 8 | BLACKROCK, INC. | 2012383 | 5.55M | 25.94M | Jun 30, 2026 |
| 9 | KALEHUA CAPITAL MANAGEMENT LLC | 2106181 | 3.72M | 17.39M | Jun 30, 2026 |
| 10 | VANGUARD CAPITAL MANAGEMENT LLC | 2100119 | 3.72M | 17.35M | Jun 30, 2026 |
| 11 | VANGUARD GROUP INC | 102909 | 3.42M | 13.69M | Dec 31, 2025 |
| 12 | ROSALIND ADVISORS, INC. | 1622627 | 3.21M | 15.01M | Jun 30, 2026 |
| 13 | BRAIDWELL LP | 1920938 | 2.92M | 13.65M | Jun 30, 2026 |
| 14 | BLACKSTONE INC. | 1393818 | 2.68M | 12.52M | Jun 30, 2026 |
| 15 | TRAILS EDGE CAPITAL PARTNERS, LP | 2077247 | 2.57M | 12.01M | Jun 30, 2026 |
| 16 | NANTAHALA CAPITAL MANAGEMENT, LLC | 1472322 | 2.45M | 11.44M | Jun 30, 2026 |
| 17 | BVF INC/IL | 1056807 | 2.23M | 10.43M | Jun 30, 2026 |
| 18 | GEODE CAPITAL MANAGEMENT, LLC | 1214717 | 2.10M | 9.80M | Jun 30, 2026 |
| 19 | VENROCK ADVISER, LLC | 1615982 | 1.93M | 9.03M | Jun 30, 2026 |
| 20 | SIREN, L.L.C. | 2005245 | 1.50M | 6M | Dec 31, 2025 |
Data sourced from SEC Form 13F institutional holdings reports. Positions reflect the most recent filing per institution.