BOSTON, MA
X4 PHARMACEUTICALS, INCXFOR— Latest position per institution from SEC 13F filings
15
Institutional holders
86.84M
Total shares held
358.01M
Estimated value
4.34M
Avg. position size
MORGAN STANLEY
CIK 895421
Shares
9.47M
Value
39.10M
Filed
Mar 31, 2026
EMPERY ASSET MANAGEMENT, LP
CIK 1469336
Shares
8.94M
Value
36.94M
Filed
Mar 31, 2026
FMR LLC
CIK 315066
Shares
8.10M
Value
33.47M
Filed
Mar 31, 2026
BAIN CAPITAL LIFE SCIENCES INVESTORS, LLC
CIK 1703031
Shares
7.97M
Value
32.91M
Filed
Mar 31, 2026
PERCEPTIVE ADVISORS LLC
CIK 1224962
Shares
6.74M
Value
27.83M
Filed
Mar 31, 2026
SATURN V CAPITAL MANAGEMENT LP
CIK 1964437
Shares
6.46M
Value
26.67M
Filed
Mar 31, 2026
DEEP TRACK CAPITAL, LP
CIK 1856083
Shares
6.34M
Value
26.18M
Filed
Mar 31, 2026
KALEHUA CAPITAL MANAGEMENT LLC
CIK 2106181
Shares
3.72M
Value
15.38M
Filed
Mar 31, 2026
VANGUARD CAPITAL MANAGEMENT LLC
CIK 2100119
Shares
3.50M
Value
14.45M
Filed
Mar 31, 2026
VANGUARD GROUP INC
CIK 102909
Shares
3.42M
Value
13.69M
Filed
Dec 31, 2025
BRAIDWELL LP
CIK 1920938
Shares
3.27M
Value
13.52M
Filed
Mar 31, 2026
ROSALIND ADVISORS, INC.
CIK 1622627
Shares
3.21M
Value
13.28M
Filed
Mar 31, 2026
BLACKSTONE INC.
CIK 1393818
Shares
2.68M
Value
11.08M
Filed
Mar 31, 2026
TRAILS EDGE CAPITAL PARTNERS, LP
CIK 2077247
Shares
2.57M
Value
10.62M
Filed
Mar 31, 2026
NANTAHALA CAPITAL MANAGEMENT, LLC
CIK 1472322
Shares
2.45M
Value
10.12M
Filed
Mar 31, 2026
BVF INC/IL
CIK 1056807
Shares
2.23M
Value
9.23M
Filed
Mar 31, 2026
SAMSARA BIOCAPITAL, LLC
CIK 1744967
Shares
1.83M
Value
7.57M
Filed
Mar 31, 2026
SIREN, L.L.C.
CIK 2005245
Shares
1.50M
Value
6M
Filed
Dec 31, 2025
BLACKROCK, INC.
CIK 2012383
Shares
1.21M
Value
5M
Filed
Mar 31, 2026
MILLENNIUM MANAGEMENT LLC
CIK 1273087
Shares
1.21M
Value
5M
Filed
Mar 31, 2026
| # | Institution | CIK | Shares | Est. Value | Period |
|---|---|---|---|---|---|
| 1 | MORGAN STANLEY | 895421 | 9.47M | 39.10M | Mar 31, 2026 |
| 2 | EMPERY ASSET MANAGEMENT, LP | 1469336 | 8.94M | 36.94M | Mar 31, 2026 |
| 3 | FMR LLC | 315066 | 8.10M | 33.47M | Mar 31, 2026 |
| 4 | BAIN CAPITAL LIFE SCIENCES INVESTORS, LLC | 1703031 | 7.97M | 32.91M | Mar 31, 2026 |
| 5 | PERCEPTIVE ADVISORS LLC | 1224962 | 6.74M | 27.83M | Mar 31, 2026 |
| 6 | SATURN V CAPITAL MANAGEMENT LP | 1964437 | 6.46M | 26.67M | Mar 31, 2026 |
| 7 | DEEP TRACK CAPITAL, LP | 1856083 | 6.34M | 26.18M | Mar 31, 2026 |
| 8 | KALEHUA CAPITAL MANAGEMENT LLC | 2106181 | 3.72M | 15.38M | Mar 31, 2026 |
| 9 | VANGUARD CAPITAL MANAGEMENT LLC | 2100119 | 3.50M | 14.45M | Mar 31, 2026 |
| 10 | VANGUARD GROUP INC | 102909 | 3.42M | 13.69M | Dec 31, 2025 |
| 11 | BRAIDWELL LP | 1920938 | 3.27M | 13.52M | Mar 31, 2026 |
| 12 | ROSALIND ADVISORS, INC. | 1622627 | 3.21M | 13.28M | Mar 31, 2026 |
| 13 | BLACKSTONE INC. | 1393818 | 2.68M | 11.08M | Mar 31, 2026 |
| 14 | TRAILS EDGE CAPITAL PARTNERS, LP | 2077247 | 2.57M | 10.62M | Mar 31, 2026 |
| 15 | NANTAHALA CAPITAL MANAGEMENT, LLC | 1472322 | 2.45M | 10.12M | Mar 31, 2026 |
| 16 | BVF INC/IL | 1056807 | 2.23M | 9.23M | Mar 31, 2026 |
| 17 | SAMSARA BIOCAPITAL, LLC | 1744967 | 1.83M | 7.57M | Mar 31, 2026 |
| 18 | SIREN, L.L.C. | 2005245 | 1.50M | 6M | Dec 31, 2025 |
| 19 | BLACKROCK, INC. | 2012383 | 1.21M | 5M | Mar 31, 2026 |
| 20 | MILLENNIUM MANAGEMENT LLC | 1273087 | 1.21M | 5M | Mar 31, 2026 |
Data sourced from SEC Form 13F institutional holdings reports. Positions reflect the most recent filing per institution.