X4 Pharmaceuticals Inc
Ownership
Ownership Structure
Who owns X4 Pharmaceuticals Inc (XFOR)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 63.3% of the shares are freely tradable; institutional investors hold 101.3%.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Morgan Stanley - Brokerage Accounts | 9.55 | 9,466,992 | +15.3 | 03/31/2026 |
| FMR Inc | 8.17 | 8,103,400 | -4.7 | 03/31/2026 |
| Bain Capital Life Sciences Investors, LLC | 8.04 | 7,967,454 | +0.0 | 03/31/2026 |
| Perceptive Advisors LLC | 8.00 | 7,933,491 | +17.7 | 06/30/2026 |
| Kalehua Capital Management LLC | 7.51 | 7,445,680 | +100.0 | 03/31/2026 |
| Saturn V Capital Management LLC | 7.03 | 6,973,343 | +8.0 | 06/30/2026 |
| Empery Asset Management, LP | 6.99 | 6,930,591 | -22.5 | 06/30/2026 |
| Deep Track Capital, LP | 5.93 | 5,878,757 | -7.3 | 06/30/2026 |
| Vanguard Capital Management, LLC | 3.53 | 3,497,612 | +0.0 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Fidelity Small Cap Growth | 3.42 | 3,386,200 | +0.0 | 06/30/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Insider holdings
| Person | Role | Shares | Value | As of | Type |
|---|---|---|---|---|---|
| Craig Adam R | Executive Chairman | 328,651 | 985,953 $ | Aug 12, 2026 | direct |
| Volpone John | President | 265,305 | 795,915 $ | Aug 12, 2026 | direct |
Holdings as of each person's most recent SEC Form 4 filing — excluding options and RSUs, which are not shares yet. Holdings may have changed between two filings.
Insiders
Insider Transactions
| Date | Person | Role | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| Aug 12, 2026 | Volpone John | President | Sell | 24,576 | 4.44 | 109,228 |
| Aug 12, 2026 | Craig Adam R | Executive Chairman | Sell | 47,436 | 4.44 | 210,829 |
Reportable transactions by officers and major shareholders from SEC Form 4 filings. "Other" includes things like stock grants and option exercises without a buy/sell character. View all insider transactions →
Data as of: September 28, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.