X4 Pharmaceuticals, Inc. (XFOR) Ownership
XFOR ownership summary
as of October 18, 2026- Institutions
- 103.8% of shares outstanding
- Insiders
- 0.44% of shares outstanding
- Shares outstanding
- 99.1M
- Float
- 57.2M shares available to trade
- Short interest
- 7.67% 7.6M shares short
- Days to cover
- 6.42 short interest down 7.8% vs prior month
- Institutions 103.83%
- Insiders 0.44%
XFOR top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Morgan Stanley - Brokerage Accounts | 9.54% | 9.5M | $24.5M | −5,713 (−0.1%) | June 30, 2026 |
| 2 | FMR Inc | 8.39% | 8.3M | $21.6M | +218,257 (+2.7%) | June 30, 2026 |
| 3 | Bain Capital Life Sciences Investors, LLC | 8.04% | 8.0M | $20.6M | — | June 30, 2026 |
| 4 | Perceptive Advisors LLC | 8.00% | 7.9M | $20.5M | +1.2M (+17.7%) | June 30, 2026 |
| 5 | Kalehua Capital Management LLC | 7.51% | 7.4M | $19.3M | — | June 30, 2026 |
| 6 | Saturn V Capital Management LLC | 7.03% | 7.0M | $18.1M | +516,697 (+8.0%) | June 30, 2026 |
| 7 | Empery Asset Management, LP | 6.99% | 6.9M | $18.0M | −2.0M (−22.5%) | June 30, 2026 |
| 8 | Deep Track Capital, LP | 5.93% | 5.9M | $15.2M | −460,778 (−7.3%) | June 30, 2026 |
| 9 | BlackRock Inc | 5.60% | 5.6M | $14.4M | +4.3M (+358.4%) | June 30, 2026 |
| 10 | Nantahala Capital Management, LLC | 4.94% | 4.9M | $12.7M | +2.4M (+100.0%) | June 30, 2026 |
| 11 | Vanguard Capital Management, LLC | 3.75% | 3.7M | $9.6M | +218,247 (+6.2%) | June 30, 2026 |
| 12 | Rosalind Advisors, Inc. | 3.24% | 3.2M | $8.3M | — | June 30, 2026 |
| 13 | BRAIDWELL LP | 2.95% | 2.9M | $7.6M | −350,200 (−10.7%) | June 30, 2026 |
| 14 | Blackstone Inc | 2.71% | 2.7M | $6.9M | — | June 30, 2026 |
| 15 | Trails Edge Capital Partners, LP | 2.59% | 2.6M | $6.7M | — | June 30, 2026 |
| 16 | Bvf Inc | 2.25% | 2.2M | $5.8M | — | June 30, 2026 |
| 17 | Geode Capital Management, LLC | 2.12% | 2.1M | $5.4M | +1.2M (+123.3%) | June 30, 2026 |
| 18 | VR Adviser, LLC | 1.95% | 1.9M | $5.0M | +1.6M (+485.2%) | June 30, 2026 |
| 19 | Samsara BioCapital, LLC | 1.41% | 1.4M | $3.6M | −436,979 (−23.8%) | June 30, 2026 |
| 20 | State Street Corp | 1.31% | 1.3M | $3.4M | +892,483 (+221.2%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 9 holders added 12.6M shares and 5 cut 3.3M.
XFOR top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Fidelity Small Cap Growth | 3.42% | 3.4M | $8.8M | — | July 31, 2026 |
| 2 | Vanguard MStar Total Stk Mkt Idx Invest | 2.62% | 2.6M | $6.7M | — | August 31, 2026 |
| 3 | Morgan Stanley Inst Inception I | 2.33% | 2.3M | $6.0M | −24,888 (−1.1%) | June 30, 2026 |
| 4 | iShares Russell 2000 ETF | 2.16% | 2.1M | $5.5M | −24,640 (−1.1%) | September 30, 2026 |
| 5 | EQ/Morgan Stanley Small Cap Growth K | 1.93% | 1.9M | $5.0M | — | August 31, 2026 |
| 6 | Fidelity Small Cap Growth K6 | 1.70% | 1.7M | $4.4M | — | July 31, 2026 |
| 7 | Fidelity Select Biotechnology | 1.44% | 1.4M | $3.7M | — | August 31, 2026 |
| 8 | Fidelity Advisor Biotechnology I | 1.35% | 1.3M | $3.5M | — | August 31, 2026 |
| 9 | Fidelity Small Cap Index | 0.89% | 885K | $2.3M | +8,957 (+1.0%) | July 31, 2026 |
| 10 | iShares Russell 2000 Value ETF | 0.77% | 762K | $2.0M | +1,154 (+0.2%) | September 30, 2026 |
| 11 | Fidelity Small Cap Stock | 0.51% | 505K | $1.3M | +166,100 (+49.1%) | July 31, 2026 |
| 12 | Vanguard Russell 2000 ETF | 0.49% | 488K | $1.3M | +23,804 (+5.1%) | September 30, 2026 |
| 13 | Fidelity Extended Market Index | 0.44% | 436K | $1.1M | +2,860 (+0.7%) | August 31, 2026 |
| 14 | iShares Micro-Cap ETF | 0.26% | 262K | $679,735 | −1,810 (−0.7%) | September 30, 2026 |
| 15 | Schwab Small Cap Index | 0.20% | 197K | $509,013 | — | August 31, 2026 |
| 16 | Fidelity Total Market Index | 0.17% | 167K | $433,390 | — | August 31, 2026 |
| 17 | iShares Russell 2000 Small-Cap Idx Instl | 0.15% | 151K | $391,450 | — | August 31, 2026 |
| 18 | Fidelity Series Total Market Index | 0.14% | 136K | $353,442 | +2,662 (+2.0%) | August 31, 2026 |
| 19 | ALPS Medical Breakthroughs ETF | 0.13% | 130K | $337,798 | — | September 30, 2026 |
| 20 | Fidelity Small Cap Value Index | 0.12% | 115K | $297,187 | +1,907 (+1.7%) | July 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
XFOR insider transactions
latest 2| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2025-10-23 | Adam R Craig | Buy | $2.90 | 86,206 | $249,997 |
| 2025-05-16 | Mark Baldry | Buy | $2.48 | 1,032 | $2,559 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
XFOR shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns XFOR
Institutional investors own 103.8% of X4 Pharmaceuticals's shares and insiders 0.44%. The largest holder is Morgan Stanley - Brokerage Accounts with 9.54% of the shares (9.5M), as of June 30, 2026. Among the top 20 institutions, 9 added shares and 5 reduced their stake in the latest filings. Short interest is 7.67% of the float, or 6.42 days of average trading volume. The share count rose 837,445.5% since 2016.
Related: XFOR analyst forecast, XFOR key metrics. See the XFOR stock overview for the latest quote and news.
XFOR ownership FAQ
Who owns the most X4 Pharmaceuticals stock?
The largest shareholders of X4 Pharmaceuticals are Morgan Stanley - Brokerage Accounts (9.54%), FMR Inc (8.39%), Bain Capital Life Sciences Investors, LLC (8.04%), Perceptive Advisors LLC (8.00%), Kalehua Capital Management LLC (7.51%).
What percentage of X4 Pharmaceuticals is owned by institutions?
Institutions hold 103.8% of X4 Pharmaceuticals's shares outstanding; insiders hold 0.44%.
Which funds own X4 Pharmaceuticals?
The largest fund holders of X4 Pharmaceuticals are Fidelity Small Cap Growth (3.42%), Vanguard MStar Total Stk Mkt Idx Invest (2.62%), Morgan Stanley Inst Inception I (2.33%), iShares Russell 2000 ETF (2.16%), EQ/Morgan Stanley Small Cap Growth K (1.93%).
What is X4 Pharmaceuticals's short interest?
7.6M shares of X4 Pharmaceuticals were sold short, 7.67% of the float; at the average daily volume it would take 6.42 days to cover.
Are insiders buying or selling X4 Pharmaceuticals?
Of the latest 2 reported insider transactions in X4 Pharmaceuticals (since May 16, 2025), 2 were purchases and 0 were sales.
How many shares of X4 Pharmaceuticals are outstanding?
X4 Pharmaceuticals has 99.1M shares outstanding, of which 57.2M are in the public float.