Ranked by reported Q4 2025 13F market value
Share of total reported institutional value in FBLG held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | VANGUARD GROUP INC | 1.2M | $274K | -1.4% | 58.032% | 0.00% |
| 2 | BlackRock, Inc. | 482K | $108K | +9.7% | 23.016% | 0.00% |
| 3 | GEODE CAPITAL MANAGEMENT, LLC | 349K | $78K | +20.7% | 16.640% | 0.00% |
| 4 | Cascade Financial Partners, LLC | 315K | $71K | +5.5% | 15.009% | 0.01% |
| 5 | MILLENNIUM MANAGEMENT LLC | 288K | $65K | -35.3% | 13.764% | 0.00% |
| 6 | RENAISSANCE TECHNOLOGIES LLC | 232K | $52K | +287.3% | 11.050% | 0.00% |
| 7 | JANE STREET GROUP, LLC | 150K | $34K | — | 7.145% | 0.00% |
| 8 | AMG National Trust Bank | 139K | $31K | — | 6.630% | 0.00% |
| 9 | UBS Group AG | 121K | $27K | +56.0% | 5.762% | 0.00% |
| 10 | STATE STREET CORP | 111K | $25K | 0.0% | 5.310% | 0.00% |
| 11 | Optivise Advisory Services LLC | 110K | $25K | 0.0% | 5.253% | 0.01% |
| 12 | Requisite Capital Management, LLC | 110K | $25K | 0.0% | 5.235% | 0.00% |
| 13 | WILEY BROS.-AINTREE CAPITAL, LLC | 100K | $22K | 0.0% | 4.771% | 0.00% |
| 14 | Cerity Partners LLC | 94K | $21K | -25.4% | 4.481% | 0.00% |
| 15 | American Institute for Advanced Investment Management, LLP | 88K | $20K | 0.0% | 4.208% | 0.01% |
| 16 | SAXON INTERESTS, INC. | 57K | $13K | +38.3% | 2.720% | 0.00% |
| 17 | BANK OF AMERICA CORP /DE/ | 48K | $11K | 0.0% | 2.298% | 0.00% |
| 18 | NORTHERN TRUST CORP | 48K | $11K | 0.0% | 2.275% | 0.00% |
| 19 | RMR Wealth Builders | 38K | $9K | 0.0% | 1.830% | 0.00% |
| 20 | XTX Topco Ltd | 38K | $9K | — | 1.809% | 0.00% |
| 21 | Concurrent Investment Advisors, LLC | 35K | $8K | 0.0% | 1.683% | 0.00% |
| 22 | Ethos Financial Group, LLC | 24K | $5K | 0.0% | 1.165% | 0.00% |
| 23 | RAYMOND JAMES FINANCIAL INC | 19K | $4K | 0.0% | 0.889% | 0.00% |
| 24 | Tower Research Capital LLC (TRC) | 18K | $4K | +6.8% | 0.864% | 0.00% |
| 25 | Cetera Investment Advisers | 18K | $4K | 0.0% | 0.859% | 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 FBLG — a direct measure of their conviction.
Filings activity in FBLG during Q4 2025, grouped by how each filer changed its position.
8 quarters of 13F filings · Δ columns show change vs prior quarter
| Quarter | Inst. Holders | Δ Holders | Ownership % | Δ Ownership | Total 13F Value | Δ Value |
|---|---|---|---|---|---|---|
| Q4 2025 | 45 | 15% | 50.54% | 128.90 pp | $1M | 72% |
| Q3 2025 | 53 | 8.6% | 179.44% | +15.99 pp | $4M | +9.8% |
| Q2 2025 | 58 | 12% | 163.45% | 36.54 pp | $3M | 45% |
| Q1 2025 | 66 | +3.1% | 199.99% | +0.00 pp | $6M | 51% |
| Q4 2024 | 64 | +3.2% | 199.99% | +0.00 pp | $12M | 30% |
| Q3 2024 | 62 | +22% | 199.99% | +0.00 pp | $17M | +3.3% |
| Q2 2024 | 51 | +183% | 199.99% | +0.00 pp | $16M | +281% |
| Q1 2024 | 18 | — | 199.99% | — | $4M | — |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Δ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying FBLG stock.
Based on Q4 2025 13F filings, institutional ownership of FibroBiologics, Inc. Common Stock stands at 50.5%, held across 45 reporting institutions.
VANGUARD GROUP INC is the largest reported institutional holder of FBLG, with approximately 1,216,341 shares worth $0.00B as of Q4 2025.
Yes — 3 widely-followed marquee investors appear among the top 25 institutional holders of FBLG, including MILLENNIUM MANAGEMENT LLC, RENAISSANCE TECHNOLOGIES LLC, JANE STREET GROUP, LLC.
Our composite Smart Money Score for FBLG is 41 out of 100 (Neutral). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
6 institutions opened new positions in FBLG during Q4 2025, while 14 fully exited. 1 added to existing positions and 36 trimmed.
FBLG institutional ownership fell by 128.90 percentage points quarter-over-quarter, with a net change of -8 holders.
The top 10 institutions account for 77.6% of all reported 13F value in FBLG, and the top 25 account for 96.9%.
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.
FibroBiologics, Inc. Common Stock (FBLG) Institutional Ownership