1y return+121.3%S&P 500 +20.9%
These returns are for its stock picks as disclosed on Form 13F: last quarter's holdings, valued at this quarter's prices. They miss trades within each quarter, short positions, options, bonds, cash and fees, so they aren't the returns its clients got.
$100 invested in its stock picks
Since September 30, 2024: $169 against $130 in the S&P 500.2
Siren, L.L.C.S&P 500 (SPY)
Top holdings
At the end of June 30, 2026. Change is in shares since the quarter before.2
| Stock | Value | Share of portfolio | Change |
|---|---|---|---|
| SRRKScholar Rock Holding Corp | $526.6M | 10.7% | −11.5% |
| KYMRKymera Therapeutics Inc | $336.7M | 6.8% | −7.9% |
| ERASErasca Inc | $208.8M | 4.2% | +1.4% |
| MANEVeradermics Inc | $203.5M | 4.1% | +10.0% |
| TNGXTango Therapeutics Inc | $193.2M | 3.9% | +9.2% |
| RVMDRevolution Medicines Inc | $168.6M | 3.4% | −19.0% |
| BCAXBicara Therapeutics Inc | $166.4M | 3.4% | −3.4% |
| ARWRArrowhead Pharmaceuticals Inc | $139.8M | 2.8% | +6.2% |
| ONCBeOne Medicines AG | $132.5M | 2.7% | |
| EWTXEdgewise Therapeutics Inc | $129.4M | 2.6% | −28.1% |
| RYTMRhythm Pharmaceuticals Inc | $126.2M | 2.6% | +56.6% |
| LXRXLexicon Pharmaceuticals Inc | $106.3M | 2.2% | |
| ELVNEnliven Therapeutics Inc | $90.1M | 1.8% | +137.8% |
| SYRESpyre Therapeutics Inc | $86.0M | 1.7% | +18.3% |
| PBLSParabilis Medicines Inc | $81.9M | 1.7% | New |
| XENEXenon Pharmaceuticals Inc | $79.6M | 1.6% | |
| SLDBSolid Biosciences Inc | $76.8M | 1.6% | |
| ABVXAbivax SA | $76.8M | 1.6% | New |
| COAGHemab Therapeutics Holdings Inc | $76.6M | 1.6% | New |
| RCUSArcus Biosciences Inc | $74.6M | 1.5% | −19.5% |
| COGTCogent Biosciences Inc | $72.0M | 1.5% | +8.8% |
| RLAYRelay Therapeutics Inc | $68.3M | 1.4% | New |
| TSHATaysha Gene Therapies Inc | $67.1M | 1.4% | +11.5% |
| DFTXDefinium Therapeutics Inc | $66.8M | 1.4% | +54.4% |
| STOKStoke Therapeutics Inc | $65.3M | 1.3% |
Best picks still held
How each current holding has done since the quarter it first appeared in its filings (up to six years back).
| Stock | Held since | Return since | Now worth |
|---|---|---|---|
| COGTCogent Biosciences Inc | June 30, 2025 | +439.0% | $72.0M |
| ARWRArrowhead Pharmaceuticals Inc | September 30, 2024 | +320.8% | $139.8M |
| RVMDRevolution Medicines Inc | September 30, 2024 | +313.0% | $168.6M |
| SYRESpyre Therapeutics Inc | December 31, 2024 | +281.4% | $86.0M |
| TSHATaysha Gene Therapies Inc | September 30, 2024 | +238.8% | $67.1M |
| STOKStoke Therapeutics Inc | December 31, 2024 | +196.6% | $65.3M |
| DFTXDefinium Therapeutics Inc | March 31, 2026 | +148.9% | $66.8M |
| KYMRKymera Therapeutics Inc | September 30, 2024 | +142.3% | $336.7M |
| RYTMRhythm Pharmaceuticals Inc | March 31, 2025 | +109.6% | $126.2M |
| RCUSArcus Biosciences Inc | September 30, 2024 | +101.6% | $74.6M |
Sold off last quarter
- Centessa Pharmaceuticals PLCCUSIP 152309100 was $41.8M
- enGene Holdings IncCUSIP 29286M105 was $35.8M
- FULCFulcrum Therapeutics Inc was $18.0M
- WAVE Life Sciences LtdCUSIP Y95308105 was $17.8M
- Uniqure NVCUSIP N90064101 was $16.4M
- BCYCBicycle Therapeutics PLC was $7.2M
- FPSForgent Power Solutions, Inc was $2.9M
- MUMicron Technology Inc was $2.0M
- Amer Sports IncCUSIP G0260P102 was $1.6M
- PRMBPrimo Brands Corp was $942K
Quarter by quarter
| Quarter | Its picks | S&P 500 |
|---|---|---|
| June 30, 2026 | +27.9% | +14.8% |
| March 31, 2026 | +5.8% | −4.6% |
| December 31, 2025 | +25.2% | +2.4% |
| September 30, 2025 | +30.7% | +7.8% |
| June 30, 2025 | +10.0% | +10.5% |
| March 31, 2025 | −18.6% | −4.6% |
| December 31, 2024 | −14.5% | +2.1% |
Sources
Every number on this page points here. Each one links to the public record.
- 1SEC EDGAR: Siren, L.L.C. Form 13F filingshttps://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=2005245&type=13F-HR&dateb=&owner=include&count=40CIK 2005245
- 2SEC: 13F for the quarter ended June 30, 2026https://www.sec.gov/Archives/edgar/data/2005245/000200524526000008/Filed August 13, 2026 · accession 0002005245-26-000008