59% buyers of institutions opening or closing positions this quarter
6 more new buyers than exits, ownership rose 8.15 percentage points vs the prior quarter, and no widely-followed fund managers in the top 25.
59% buyers of institutions opening or closing positions this quarter
76.3% institutional ownership
Empery Asset Management, portfolio allocation
Institutional ownership vs Biotechnology peers
No Form 4 insider transactions on file
Latest positioning in XFOR across 13F flow, ownership shift, marquee holders, and holder-count growth.
Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in XFOR held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | MORGAN STANLEY | 9.5M | $39.1M | +15.3% | 7.496% | 0.00% |
| 2 | Empery Asset Management, LP | 8.9M | $36.9M | -0.1% | 7.082% | 44.50% |
| 3 | FMR LLC | 8.1M | $33.5M | -4.7% | 6.417% | 0.00% |
| 4 | Bain Capital Life Sciences Investors, LLC | 8.0M | $32.9M | 0.0% | 6.309% | 2.97% |
| 5 | PERCEPTIVE ADVISORS LLC | 6.7M | $27.8M | +6.7% | 5.335% | 0.54% |
| 6 | Saturn V Capital Management LP | 6.5M | $26.7M | +11.3% | 5.113% | 4.83% |
| 7 | Deep Track Capital, LP | 6.3M | $26.2M | +26.5% | 5.020% | 0.43% |
| 8 | Kalehua Capital Management LLC | 3.7M | $15.4M | 0.0% | 2.948% | 12.96% |
| 9 | VANGUARD CAPITAL MANAGEMENT LLC | 3.5M | $14.4M | — | 2.770% | 0.00% |
| 10 | BRAIDWELL LP | 3.3M | $13.5M | -2.9% | 2.592% | 0.45% |
| 11 | Rosalind Advisors, Inc. | 3.2M | $13.3M | +23.4% | 2.546% | 5.33% |
| 12 | Blackstone Inc | 2.7M | $11.1M | 0.0% | 2.124% | 0.04% |
| 13 | Trails Edge Capital Partners, LP | 2.6M | $10.6M | 0.0% | 2.036% | 2.43% |
| 14 | Nantahala Capital Management, LLC | 2.4M | $10.1M | 0.0% | 1.940% | 0.37% |
| 15 | BVF INC/IL | 2.2M | $9.2M | 0.0% | 1.769% | 0.29% |
| 16 | Samsara BioCapital, LLC | 1.8M | $7.6M | -6.5% | 1.451% | 0.74% |
| 17 | BlackRock, Inc. | 1.2M | $5.0M | -1.2% | 0.959% | 0.00% |
| 18 | MILLENNIUM MANAGEMENT LLC | 1.2M | $5.0M | +2062.5% | 0.959% | 0.00% |
| 19 | Woodline Partners LP | 1.0M | $4.1M | +0.0% | 0.793% | 0.02% |
| 20 | GEODE CAPITAL MANAGEMENT, LLC | 940K | $3.9M | -0.1% | 0.744% | 0.00% |
| 21 | GOLDMAN SACHS GROUP INC | 882K | $3.6M | +6.0% | 0.699% | 0.00% |
| 22 | SUSQUEHANNA INTERNATIONAL GROUP, LLP | 856K | $3.5M | +470.7% | 0.678% | 0.00% |
| 23 | STEMPOINT CAPITAL LP | 851K | $3.5M | -5.3% | 0.674% | 0.68% |
| 24 | VANGUARD FIDUCIARY TRUST CO | 481K | $2.0M | — | 0.381% | 0.00% |
| 25 | STATE STREET CORP | 404K | $1.7M | +103.6% | 0.320% | 0.00% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). “% of Fund” shows how much of that investor’s total 13F portfolio is invested in XFOR — a direct measure of their conviction.
Filings activity in XFOR during Q1 2026, grouped by how each filer changed its position.
5 quarters of 13F filings · Δ columns show change vs prior quarter
| Quarter | Inst. Holders | Δ Holders | Ownership % | Δ Ownership | Total 13F Value | Δ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 81 | +8.0% | 76.27% | +8.15 pp | $374M | +8.6% |
| Q4 2025 | 75 | +88% | 68.12% | +58.88 pp | $344M | +637% |
| Q3 2025 | 40 | 22% | 9.24% | +8.44 pp | $47M | +1059% |
| Q2 2025 | 51 | +2450% | 0.80% | +0.80 pp | $4M | +14924311% |
| Q1 2025 | 2 | — | 0.00% | — | $0M | — |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Δ columns compare to the immediately prior filed quarter.
No recent Form 4 insider transactions on file for XFOR.
Quick answers to the most common questions about buying XFOR stock.
Based on Q1 2026 13F filings, institutional ownership of X4 Pharmaceuticals, Inc. stands at 76.3%, held across 81 reporting institutions.
MORGAN STANLEY is the largest reported institutional holder of XFOR, with approximately 9,466,992 shares worth $0.04B as of Q1 2026.
No marquee "smart money" managers (Berkshire, Burry, ARK, Tiger Global, Pershing Square, Baupost, etc.) currently appear among the top 25 institutional holders of XFOR.
Our composite Smart Money Score for XFOR is 50 out of 100 (Neutral). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
19 institutions opened new positions in XFOR during Q1 2026, while 13 fully exited. 43 added to existing positions and 17 trimmed.
XFOR institutional ownership rose by 8.15 percentage points quarter-over-quarter, with a net change of +6 holders.
The top 10 institutions account for 71.3% of all reported 13F value in XFOR, and the top 25 account for 96.5%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.