75% buyers of institutions opening or closing positions this quarter
43 more new buyers than exits, ownership rose 8.90 percentage points vs the prior quarter, and 1 well-known fund manager in the top 25.
75% buyers of institutions opening or closing positions this quarter
22.4% institutional ownership
VISION FINANCIAL MARKETS portfolio allocation
Institutional ownership vs Biotechnology peers
No Form 4 insider transactions on file
Latest positioning in SLS 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 SLS held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 12.2M | $51.6M | +61.8% | 8.564% | 0.00% |
| 2 | SUSQUEHANNA INTERNATIONAL GROUP, LLP | 9.0M | $38.0M | +42.1% | 6.305% | 0.00% |
| 3 | STATE STREET CORP | 8.4M | $35.5M | +283.7% | 5.895% | 0.00% |
| 4 | VANGUARD CAPITAL MANAGEMENT LLC | 7.5M | $31.8M | β | 5.284% | 0.00% |
| 5 | GEODE CAPITAL MANAGEMENT, LLC | 3.9M | $16.6M | +27.1% | 2.747% | 0.00% |
| 6 | MARSHALL WACE, LLP | 2.0M | $8.6M | +51.9% | 1.430% | 0.01% |
| 7 | JONES FINANCIAL COMPANIES LLLP | 1.7M | $7.3M | +290.2% | 1.176% | 0.00% |
| 8 | VANGUARD PORTFOLIO MANAGEMENT LLC | 1.5M | $6.2M | β | 1.027% | 0.00% |
| 9 | MORGAN STANLEY | 1.3M | $5.7M | +50.0% | 0.938% | 0.00% |
| 10 | NORTHERN TRUST CORP | 1.3M | $5.4M | +37.1% | 0.896% | 0.00% |
| 11 | VANGUARD FIDUCIARY TRUST CO | 1.2M | $5.1M | β | 0.844% | 0.00% |
| 12 | DAGCO, INC. | 1.0M | $4.4M | +78.1% | 0.722% | 0.94% |
| 13 | UBS Group AG | 745K | $3.2M | +1429.8% | 0.523% | 0.00% |
| 14 | Invesco Ltd. | 698K | $3.0M | +1209.9% | 0.490% | 0.00% |
| 15 | Nuveen, LLC | 671K | $2.8M | -34.5% | 0.471% | 0.00% |
| 16 | BANK OF AMERICA CORP /DE/ | 642K | $2.7M | +535.7% | 0.451% | 0.00% |
| 17 | GOLDMAN SACHS GROUP INC | 556K | $2.4M | +35.0% | 0.390% | 0.00% |
| 18 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 481K | $2.0M | +17.7% | 0.337% | 0.00% |
| 19 | Bank of New York Mellon Corp | 478K | $2.0M | +86.6% | 0.336% | 0.00% |
| 20 | TWO SIGMA INVESTMENTS, LP | 403K | $1.7M | -62.7% | 0.283% | 0.00% |
| 21 | Everhart Financial Group, Inc. | 364K | $1.5M | -21.8% | 0.256% | 0.13% |
| 22 | WELLINGTON MANAGEMENT GROUP LLP | 345K | $1.5M | β | 0.242% | 0.00% |
| 23 | VISION FINANCIAL MARKETS LLC | 304K | $1.3M | β | 0.214% | 1.26% |
| 24 | SIMPLEX TRADING, LLC | 295K | $1.2M | β | 0.207% | 0.00% |
| 25 | Rafferty Asset Management, LLC | 249K | $1.1M | β | 0.175% | 0.00% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). β% of Fundβ shows how much of that investorβs total 13F portfolio is invested in SLS β a direct measure of their conviction.
Filings activity in SLS during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings Β· Ξ columns show change vs prior quarter
| Quarter | Inst. Holders | Ξ Holders | Ownership % | Ξ Ownership | Total 13F Value | Ξ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 151 | +40% | 22.40% | +8.90 pp | $259M | +66% |
| Q4 2025 | 108 | +20% | 13.50% | +8.67 pp | $156M | +179% |
| Q3 2025 | 90 | +17% | 4.83% | 0.12 pp | $56M | 2.5% |
| Q2 2025 | 77 | +79% | 4.95% | +3.59 pp | $57M | +263% |
| Q1 2025 | 43 | +39% | 1.36% | +0.81 pp | $16M | +148% |
| Q4 2024 | 31 | 3.1% | 0.55% | 0.02 pp | $6M | 3.1% |
| Q3 2024 | 32 | +6.7% | 0.57% | +0.18 pp | $7M | +47% |
| Q2 2024 | 30 | β | 0.39% | β | $4M | β |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Ξ columns compare to the immediately prior filed quarter.
No recent Form 4 insider transactions on file for SLS.
Quick answers to the most common questions about buying SLS stock.
Based on Q1 2026 13F filings, institutional ownership of SELLAS Life Sciences Group, Inc. stands at 22.4%, held across 151 reporting institutions.
BlackRock, Inc. is the largest reported institutional holder of SLS, with approximately 12,198,410 shares worth $0.05B as of Q1 2026.
Yes β 1 widely-followed marquee investor appear among the top 25 institutional holders of SLS, including TWO SIGMA INVESTMENTS, LP.
Our composite Smart Money Score for SLS is 65 out of 100 (Bullish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
64 institutions opened new positions in SLS during Q1 2026, while 21 fully exited. 69 added to existing positions and 17 trimmed.
SLS institutional ownership rose by 8.90 percentage points quarter-over-quarter, with a net change of β holders.
The top 10 institutions account for 79.8% of all reported 13F value in SLS, and the top 25 account for 93.6%.
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.